PHP在链接后保持会话登录

我写了一个页面，显示了MySQL数据库中的大量数据，所有的工作都很完美，除了当我点击主页链接时，它会注销页面的标题，我需要重新登录，我可能错过了一些愚蠢的事情，或者没有做我需要的事情，下面的代码

<?php
session_start();
?><title>Vend365 Monitor (Beta test)</title>
<h1><u><a href="http://www.codeman.org/v365.php">Vend 365 online monitor (Beta test)</a><p></p></u></h3>
<?php
require_once ("V365Connect.php");
//Following if 'update' is clicked
if (isset($_POST['lastseen'])){?><p>
<style>
table, th, td {
    border: 1px solid black;
    border-collapse: collapse;
}
th, td {
    padding: 1px;
    text-align: left;    
}
</style>
<h1>Vend 'Last Seen' times: Page loaded at <?php echo date("d/m/Y G:i:s"); ?></h1>
    <?php
$result1 = mysql_query("SELECT distinct customer FROM vends order by customer") or die(mysql_error());  
  while($row = mysql_fetch_assoc($result1)) 
  {  echo '<table><th>';
    ?><font size = "5">Customer - '<?php echo $row[customer];?>'</font><?php
    echo '</th>';
    $result2 = mysql_query("SELECT * FROM vends where customer ='".$row[customer]."'") or die(mysql_error());  
  while($row1 = mysql_fetch_assoc($result2)) 
 {
    echo '<tr><td>';
    ?>Machine <b>'<?php echo $row1[machine];?>'</b> last seen online at <b>'<?php echo $row1[lastseen];?>'</b> running version <b>'<?php echo $row1[myversion];?>'</b><?php
    $today = date("d/m/Y G:i:s");
    $lastseentime = $row1[lastseen];
    $diff = $today-$lastseentime;
    if ($diff == "1"){
    ?><b> <font color = "red"> -- Last seen online yesterday</font></b> <?php ;}
    if ($diff > "1"){
    ?> <b><font color = "red"> -- Last seen online BEFORE yesterday</font></b> <?php ;}
    echo '</td></tr><p>' ;
 }
 }?></table>
<?php
}else{
if (isset($_POST['update'])){
if ($_POST['checkbox']=='checked'){
$isalive = 1;
} else {
$isalive = 0;
}
if ($_POST['checkbox1']=='checked'){
$hb800 = 1;
} else {
$hb800 = 0;
}
if ($_POST['checkbox2']=='checked'){
$hb1100 = 1;
} else {
$hb1100 = 0;
}
if ($_POST['checkbox3']=='checked'){
$hb1400 = 1;
} else {
$hb1400 = 0;
}
if ($_POST['checkbox4']=='checked'){
$hb1700 = 1;
} else {
$hb1700 = 0;
}
if ($_POST['checkbox5']=='checked'){
$gcmreboot = 1;
} else {
$gcmreboot = 0;
}
if ($_POST['checkbox6']=='checked'){
$emailreboot = 1;
} else {
$emailreboot = 0;
}
if ($_POST['checkbox7']=='checked'){
$hbgcm = 1;
} else {
$hbgcm = 0;
}
if ($_POST['checkbox8']=='checked'){
$hbemail = 1;
} else {
$hbemail = 0;
}
if ($_POST['checkbox9']=='checked'){
$edigcm = 1;
} else {
$edigcm = 0;
}
if ($_POST['checkbox10']=='checked'){
$ediemail = 1;
} else {
$ediemail = 0;
}
if ($_POST['checkbox11']=='checked'){
$reportgcm = 1;
} else {
$reportgcm = 0;
}
if ($_POST['checkbox12']=='checked'){
$reportemail = 1;
} else {
$reportemail = 0;
}
if ($_POST['checkbox13']=='checked'){
$pingmailgcm = 1;
} else {
$pingmailgcm = 0;
}
if ($_POST['checkbox14']=='checked'){
$pingmailemail = 1;
} else {
$pingmailemail = 0;
}
if ($_POST['checkbox15']=='checked'){
$internetgcm = 1;
} else {
$internetgcm = 0;
}
if ($_POST['checkbox16']=='checked'){
$internetemail= 1;
} else {
$internetemail = 0;
}
if ($_POST['checkbox17']=='checked'){
$sqlgcm = 1;
} else {
$sqlgcm = 0;
}
if ($_POST['checkbox18']=='checked'){
$sqlemail = 1;
} else {
$sqlemail = 0;
}
if ($_POST['checkbox19']=='checked'){
$backupgcm = 1;
} else {
$backupgcm = 0;
}
if ($_POST['checkbox20']=='checked'){
$backupemail = 1;
} else {
$backupemail = 0;
}
$sqlupdate = "update vends set isalive='".$isalive."',customer='".$_POST['customer']."',machine='".$_POST['machine']."',mailserver='".$_POST['smtp']."',emails='".$_POST['emails']."',gcm='".$_POST['gcm']."',hb800='".$hb800."',hb1100='".$hb1100."',hb1400='".$hb1400."',hb1700='".$hb1700."',sqlserver='".$_POST['sqlserver']."',sqlport='".$_POST['sqlport']."',sqlinstance='".$_POST['sqlinstance']."',sqldatabase='".$_POST['sqldatabase']."',sqlname='".$_POST['sqlname']."',sqlpassword='".$_POST['sqlpassword']."',rebootgcm='".$gcmreboot."',rebootemail='".$emailreboot."',hbgcm='".$hbgcm."',hbemail='".$hbemail."',edigcm='".$edigcm."',ediemail='".$ediemail."',reportgcm='".$reportgcm."',reportemail='".$reportemail."',mailpinggcm='".$pingmailgcm."',mailpingemail='".$pingmailemail."',internetgcm='".$internetgcm."',internetemail='".$internetemail."',sqlgcm='".$sqlgcm."',sqlemail='".$sqlemail."',backupgcm='".$backupgcm."',backupemail='".$backupemail."',lastseen='".$lastseen."' where mac='".$_SESSION['mac']."'";
mysql_query($sqlupdate) or die(mysql_error());?><h1>
--->Customer -  <font color = blue><?php echo $_SESSION['customer'];?></font>
<br />
--->Machine - <font color = blue><?php echo $_SESSION['machine'];?></font>
<p>
<?php 
echo "Request sent";
}
else
{
//First load screen to select customer when correct details are entered
if (!isset($_POST['update'])){
if (!isset($_POST['customer'])){
if (!isset($_POST['machine'])){
if (isset($_POST['submit'])){
$result = mysql_query("SELECT * FROM users where user='".$_POST['user']."' and pass='".$_POST['pass']."'") or die(mysql_error()); 
$count = mysql_num_rows($result);
if ($count == 1){
?><p><p> <table style="border:1px solid black;"><tr><td><h1>Welcome '<?php echo $_POST['user'];?>'</td></tr></table><?php 
$_SESSION['customer'];
$_SESSION['machine'];
$_SESSION['mac'];
if (!isset($_POST['customer'])) {
if (!isset($_POST['machine'])) {
echo "<h1><form action ='' method='post'>";
echo "Please Select Your Customer<br />";
$result1 = mysql_query("SELECT distinct customer FROM vends order by customer") or die(mysql_error());  
 echo "<select name='customer'>"; 
 while($row = mysql_fetch_assoc($result1)) 
 { 
    echo "<option value = '".$row[customer]."'>".$row[customer]."</option>"; 
 }
echo "</select>";
echo "<input type='submit' value='Go'>";
echo "</form>";
echo "";
echo "Show all 'Last Seen' times";
?>
<form method='post'>
<input type='submit' value='Show Last Seen Status' name ='lastseen' />
</form>
<?php
}
}}else {
// If wrong details entered
echo "Sorry, wrong username or password, please go back and try again";
}
} else {
// Following is first time load screen
?>
<!DOCTYPE HTML> <html> 
<head> 
<link rel="stylesheet" type="text/css" href="style-sign.css"> 
</head><h1> 
<title>Vend 365 Monitor</title>
<body id="body-color"> 
<div id="Sign-In"> 
<fieldset style="width:30%">
<legend>LOG-IN HERE</legend>

<form method="POST"> User <br><input type="text" style="font-size: 30px;" name="user" size="20"><br> Password <br><input type="password" style="font-size: 30px;" name="pass" size="20"><br> 
<input id="button" type="submit" style="font-size: 30px; "name="submit" value="Log-In"> </form> </fieldset> 
</div> 
</body> 
</html> 
<?php
}}} 
} else {

}
?>
<?php
// Select a vending machine
if (!isset($_POST['submit'])){
 if (isset($_POST['customer'])) {
    $example = $_POST['customer'];
    $_SESSION['customer'] = $example;
$result2 = mysql_query("SELECT * FROM vends where customer='".$example."'") or die(mysql_error()); 
?><h1>
<font color = black>--->Customer - <font color = blue><?php
echo $_SESSION['customer'];?><p></font></font><?php
    echo "<form action ='' method='post'>"; 
echo "Please Select Your Machine<br />";
 echo "<select name='machine'>"; 
 while($row = mysql_fetch_assoc($result2)) 
 { 
    echo "<option value = '".$row[machine]."'>".$row[machine]."</option>"; 
 }
echo "</select>";
echo "<input type='submit' value='Go'>";
echo "</form>";

    }}
    // show all customer/machine info
 if (isset($_POST['machine'])) {
    $example1 = $_POST['machine'];
    $_SESSION['machine'] = $example1;?>
<h1><font color = black>--->Customer - <font color = blue><?php
echo $_SESSION['customer'];?><br /></font></font><br /><font color = black>--->Machine - <font color = blue><?php
    echo $_SESSION['machine'];  ?><p><?php
$result3 = mysql_query("SELECT * FROM vends where customer='".$_SESSION['customer']."' and machine ='".$_SESSION['machine']."'") or die(mysql_error()); 
while ($rows = mysql_fetch_assoc($result3))
{
$tag1 = $rows['hb800'];
    $checkedstatus1 = '';
    if($tag1 == '1')
    {
      $checkedstatus1 = 'checked';
    } else {
    $checkedstatus1 = 'unchecked'; 
    }?><font color = black><form method='post'>
0800 Heartbeat check - <input type='checkbox' value='checked' name='checkbox1' <?php echo $checkedstatus1; ?> />
<br /><?php
$tag2 = $rows['hb1100'];
    $checkedstatus2 = '';
    if($tag2 == '1')
    {
      $checkedstatus2 = 'checked';
    } else {
    $checkedstatus2 = 'unchecked'; 
    }?>
1100 Heartbeat check- <input type='checkbox' value='checked' name='checkbox2' <?php echo $checkedstatus2; ?> />
<br />
<?php $tag3 = $rows['hb1400'];
    $checkedstatus3 = '';
    if($tag3 == '1')
    {
      $checkedstatus3 = 'checked';
    } else {
    $checkedstatus3 = 'unchecked'; 
    }?>
1400 Heartbeat check - <input type='checkbox' value='checked' name='checkbox3' <?php echo $checkedstatus3; ?> />
<br />
<?php 
$tag4 = $rows['hb1700'];
    $checkedstatus4 = '';
    if($tag4 == '1')
    {
      $checkedstatus4 = 'checked';
    } else {
    $checkedstatus4 = 'unchecked'; 
    }?>
1700 Heartbeat check - <input type='checkbox' value='checked' name='checkbox4' <?php echo $checkedstatus4; ?> /><br />
<?php 
$tag5 = $rows['rebootgcm'];
    $checkedstatus5 = '';
    if($tag5 == '1')
    {
      $checkedstatus5 = 'checked';
    } else {
    $checkedstatus5 = 'unchecked'; 
    }?>
Send GCM when rebooted - <input type='checkbox' value='checked' name='checkbox5' <?php echo $checkedstatus5; ?> /><br />
<?php 
$tag6 = $rows['rebootemail'];
    $checkedstatus6 = '';
    if($tag6 == '1')
    {
      $checkedstatus6 = 'checked';
    } else {
    $checkedstatus6 = 'unchecked'; 
    }?>
Send email when rebooted - <input type='checkbox' value='checked' name='checkbox6' <?php echo $checkedstatus6; ?> /><br />
<?php 
$tag7 = $rows['hbgcm'];
    $checkedstatus7 = '';
    if($tag7 == '1')
    {
      $checkedstatus7 = 'checked';
    } else {
    $checkedstatus7 = 'unchecked'; 
    }?>
Heartbeat check GCM - <input type='checkbox' value='checked' name='checkbox7' <?php echo $checkedstatus7; ?> /><br />
<?php 
$tag8 = $rows['hbemail'];
    $checkedstatus8 = '';
    if($tag8 == '1')
    {
      $checkedstatus8 = 'checked';
    } else {
    $checkedstatus8 = 'unchecked'; 
    }?>
Heartbeat check Email - <input type='checkbox' value='checked' name='checkbox8' <?php echo $checkedstatus8; ?> /><br />
<?php 
$tag9 = $rows['edigcm'];
    $checkedstatus9 = '';
    if($tag9 == '1')
    {
      $checkedstatus9 = 'checked';
    } else {
    $checkedstatus9 = 'unchecked'; 
    }?>
EDI fail check GCM - <input type='checkbox' value='checked' name='checkbox9' <?php echo $checkedstatus9; ?> /><br />
<?php 
$tag10 = $rows['ediemail'];
    $checkedstatus10 = '';
    if($tag10 == '1')
    {
      $checkedstatus10 = 'checked';
    } else {
    $checkedstatus10 = 'unchecked'; 
    }?>
EDI fail check Email - <input type='checkbox' value='checked' name='checkbox10' <?php echo $checkedstatus10; ?> /><br />
<?php 
$tag11 = $rows['reportgcm'];
    $checkedstatus11 = '';
    if($tag11 == '1')
    {
      $checkedstatus11 = 'checked';
    } else {
    $checkedstatus11 = 'unchecked'; 
    }?>
Report fail GCM - <input type='checkbox' value='checked' name='checkbox11' <?php echo $checkedstatus11; ?> /><br />
<?php 
$tag12 = $rows['reportemail'];
    $checkedstatus12 = '';
    if($tag12 == '1')
    {
      $checkedstatus12 = 'checked';
    } else {
    $checkedstatus12 = 'unchecked'; 
    }?>
Report fail Email - <input type='checkbox' value='checked' name='checkbox12' <?php echo $checkedstatus12; ?> /><br />
<?php 

$gcm = $rows[gcm];
$tag13 = $rows['mailpinggcm'];
    $checkedstatus13 = '';
    if($tag13 == '1')
    {
      $checkedstatus13 = 'checked';
    } else {
    $checkedstatus13 = 'unchecked'; 
    }?>
Ping email server GCM - <input type='checkbox' value='checked' name='checkbox13' <?php echo $checkedstatus13; ?> /><br />  
<?php 

$tag14 = $rows['mailpingemail'];
    $checkedstatus14 = '';
    if($tag14 == '1')
    {
      $checkedstatus14 = 'checked';
    } else {
    $checkedstatus14 = 'unchecked'; 
    }?>
Ping email server Email - <input type='checkbox' value='checked' name='checkbox14' <?php echo $checkedstatus14; ?> /><br /> 
<?php 

$tag15 = $rows['internetgcm'];
    $checkedstatus15 = '';
    if($tag15 == '1')
    {
      $checkedstatus15 = 'checked';
    } else {
    $checkedstatus15 = 'unchecked'; 
    }?>
Ping internet fail GCM - <input type='checkbox' value='checked' name='checkbox15' <?php echo $checkedstatus15; ?> /><br /> 
<?php 

$tag16 = $rows['internetemail'];
    $checkedstatus16 = '';
    if($tag16 == '1')
    {
      $checkedstatus16 = 'checked';
    } else {
    $checkedstatus16 = 'unchecked'; 
    }?>
Ping internet fail email - <input type='checkbox' value='checked' name='checkbox16' <?php echo $checkedstatus16; ?> /><br /> 
<?php 

$tag17 = $rows['sqlgcm'];
    $checkedstatus17 = '';
    if($tag17 == '1')
    {
      $checkedstatus17 = 'checked';
    } else {
    $checkedstatus17 = 'unchecked'; 
    }?>
Failed SQL ping GCM - <input type='checkbox' value='checked' name='checkbox17' <?php echo $checkedstatus17; ?> /><br /> 
<?php 

$tag18 = $rows['sqlemail'];
    $checkedstatus18 = '';
    if($tag18 == '1')
    {
      $checkedstatus18 = 'checked';
    } else {
    $checkedstatus18 = 'unchecked'; 
    }?>
Failed SQL ping email - <input type='checkbox' value='checked' name='checkbox18' <?php echo $checkedstatus18; ?> /><br /> 
<?php 

$tag19 = $rows['backupgcm'];
    $checkedstatus19 = '';
    if($tag19 == '1')
    {
      $checkedstatus19 = 'checked';
    } else {
    $checkedstatus19 = 'unchecked'; 
    }?>
Backup fail GCM - <input type='checkbox' value='checked' name='checkbox19' <?php echo $checkedstatus19; ?> /><br /> 
<?php 

$tag20 = $rows['backupemail'];
    $checkedstatus20 = '';
    if($tag20 == '1')
    {
      $checkedstatus20 = 'checked';
    } else {
    $checkedstatus20 = 'unchecked'; 
    }?>
Backp fail email - <input type='checkbox' value='checked' name='checkbox20' <?php echo $checkedstatus20; ?> /><br /> 

<u><b><p>Details</b></u><p>
<?php $_SESSION['mac'] = $rows[mac]; ?>
Mac address - '<?php echo $_SESSION['mac']; ?>'<br />
Customer name - '<?php echo $rows[customer]; ?>'<br />
Machine name - '<?php echo $rows[machine]; ?>'<br />
Current version - '<?php echo $rows[myversion]; ?>'<br />
GCM app code - <input type='text' value='<?php echo $gcm; ?>' size=150 rows=4 name='gcm' />......<br />
SMTP server - '<?php echo $rows[mailserver]; ?>'<br />
Email addresses (seperate by commas) - '<?php echo $rows[emails]; ?>'<br /><p>
<u><b>SQL Credentials</b></u><p>
SQL server - '<?php echo $rows[sqlserver]; ?>'<br />
SQL Port - '<?php echo $rows[sqlport]; ?>'<br />
SQL Instance - '<?php echo $rows[sqlinstance] ?>'<br />
SQL Database - '<?php echo $rows[sqldatabase]; ?>'<br />
SQL User name - '<?php echo $rows[sqlname]; ?>'<br />
SQL Password - '<?php echo $rows[sqlpassword]; ?>' <br /><p>
<p>
<u><b>Alive status</u></b><p>
Last seen online - '<?php echo $rows[lastseen]; ?>'<br />
<?php
$tag = $rows['isalive'];
    $checkedstatus = '';
    if($tag == '1')
    {
      $checkedstatus = 'checked';
    } else {
    $checkedstatus = 'unchecked'; 
    }?>
Request 'IsAlive' status - <input type='checkbox' value='checked' name='checkbox' <?php echo $checkedstatus; ?> /> - This will send a GCM and Email if alive.<p>
<input type='submit' value='Update account details' name ='update' /><p>
</form><p>
    <?php
    }}}}
    ?>

---

TL；博士，能不能请你适当缩进你的代码，使它容易阅读；DR-你能只发布相关代码吗？你有会话启动吗；在每一页上？这是什么疯狂？不要过于挑剔，但这段代码完全不可读，似乎体现了所有最佳实践的极端对立。你需要积极地重构它，因为它已经失控了。至少你需要读一本指南，因为这都是错的。缩进？？对不起，我不知道那是什么意思。