在php中使用javascript进行验证

我想使用JavaScript验证我的联系人表单，但我不知道验证代码以及在哪里包括

我希望在重定向到thank_you.php页面之前进行验证

请帮我

HTML

formcode.php

database.php

---

在提交表单之前使用javascript执行验证，如下所示。首先给你的表单提供id，这样你可以通过JS轻松提交

<form method='post' action="database.php" id='frm'></form>
make a call to validate function from the submit button like this

<input type='submit' value='Button' onclick=javacript:validate(); />


 <script language=javascript> //easy one by one validation. this allow full control
     function validate(){
        if (document.getElementById('name').value==''){
            alert('name is required');//customize this for your need. You may use div display
             return;
         }                         
          //repeat the above for each form tags and values

         document.getElementById('frm').submit();//submit the form
    }

 </script>

---

还有更高级的验证，上面是简单的原语方法

尝试编写一些验证代码，这样我们可以帮助您，如果您无法使其正常工作，您也必须用PHP验证表单，而不仅仅依赖JS验证。如果您想用JavaScript验证，或者甚至在数据发送到database.php之前。但是初学者可以从这里开始。谢谢，我已经按照您的指导做了相应的工作，验证正在工作。。。。

<form method='post' action="database.php">
  NAME: <input type='text' name='name' id='name' />
  Email: <input type='text' name='email' id='email' />
  Contact: <input type='text' name='contact' id='contact' />
  Tour:
   <select  id="tour" name="tour" >
        <option value="">--Select Tours--</option>
        <option value="Tour1">Tour1</option>
        <option value="Tour2">Tour2</option>

    </select><br/>
  Location:
    <select  id="location" name="location" >
        <option value="">--Select Your Location--</option>
        <option value="Loc1">Loc1</option>
        <option value="Loc2">Loc2</option>
    </select><br/>   
  Comment:<br />
  <textarea name='comment' id='comment' /></textarea><br />

  <input type='submit' value='Submit' />  

</form>

<?php
if( $_POST )
{
  $con = mysql_connect("localhost","root","");

  if (!$con)
  {
    die('Could not connect: ' . mysql_error());
  }

  mysql_select_db("db_name", $con);

  $users_name = $_POST['name'];
  $users_email = $_POST['email'];
  $users_contact = $_POST['contact'];
  $users_tour = $_POST['tour'];
  $users_location = $_POST['location'];
  $users_comment = $_POST['comment'];

  $users_name = mysql_real_escape_string($users_name);
  $users_email = mysql_real_escape_string($users_email);
  $users_contact = mysql_real_escape_string($users_contact);
  $users_tour = mysql_real_escape_string($users_tour);
  $users_location = mysql_real_escape_string($users_location);
  $users_comment = mysql_real_escape_string($users_comment);

  $query = "
  INSERT INTO `db_name`.`dbtable` (`id`, `name`, `email`, `contact`, `tour`, `location`, `comment`, `timestamp`, `articleid`)
  VALUES ( Null, '$users_name', '$users_email', '$users_contact', '$users_tour', '$users_location', '$users_comment', CURRENT_TIMESTAMP);";

  mysql_query($query);

  $url = 'thank_you.php';
  echo '<META HTTP-EQUIV=Refresh CONTENT="0; URL='.$url.'">';

  mysql_close($con);

  include("mail.php"); 
}
?>

<form method='post' action="database.php" id='frm'></form>
make a call to validate function from the submit button like this

<input type='submit' value='Button' onclick=javacript:validate(); />


 <script language=javascript> //easy one by one validation. this allow full control
     function validate(){
        if (document.getElementById('name').value==''){
            alert('name is required');//customize this for your need. You may use div display
             return;
         }                         
          //repeat the above for each form tags and values

         document.getElementById('frm').submit();//submit the form
    }

 </script>