循环中的Javascript函数工作不正常？

我有一些html代码

<table class="layout" border="0" width="90%" align="center">

<form name="addcust" action="insrtCustomer.php" method="post" onsubmit="return validateall(this);">

    <td colspan="2">

    <table border="0" width="70%" align="center">

<tr>
    <td align="center" colspan="2">

    <div class="heading2">Infy Bank</div>

    </td>
</tr>

<tr>
    <td align="center" colspan="2"><p class="heading3">Add New Customer</p></td>

</tr>
<tr>
</tr>
<tr>
</tr>

<!--comments: To display customer name field-->

<tr>
    <td>Customer Name<span class="mandatory">*</span></td><td><input type="text" name="name" maxlength="25" onKeyUp="validatecustomername();" onBlur="validatecustomername();"><label id="message"></label></td>

</tr>

<!--comments: To display customer gender field-->

<tr>
    <td>Gender<span class="mandatory">*</span></td><td>
    <input type ="radio" name ="rad1" value="1" checked>male
    <input type ="radio" name ="rad1" value="1">female
    </td>
</tr>

<!--comments: To display customer date of birth field-->

<tr>
        <td>Date of Birth <span class="mandatory">*</span></td>
        <td> <select name ="day">
        <option value ="1">1</option>
        <option value ="2">2</option>
        <option value ="3">3</option>
        <option value ="4">4</option>
        <option value ="5">5</option>
        <option value ="6">6</option>
        <option value ="7">7</option>
        <option value ="8">8</option>
        <option value ="9">9</option>
        <option value ="10">10</option>
        <option value ="11">11</option>
        <option value ="12">12</option>
        <option value ="13">13</option>
        <option value ="14">14</option>
        <option value ="15">15</option>
        <option value ="16">16</option>
        <option value ="17">17</option>
        <option value ="18">18</option>
        <option value ="19">19</option>
        <option value ="20">20</option>
        <option value ="21">21</option>
        <option value ="22">22</option>
        <option value ="23">23</option>
        <option value ="24">24</option>
        <option value ="25">25</option>
        <option value ="26">26</option>
        <option value ="27">27</option>
        <option value ="28">28</option>
        <option value ="29">29</option>
        <option value ="30">30</option>
        <option value ="31">31</option>
        </select>
        <select name ="month">
        <option value ="1">JAN</option>
        <option value ="2">FEB</option>
        <option value ="3">MAR</option>
        <option value ="4">APR</option>
        <option value ="5">MAY</option>
        <option value ="6">JUN</option>
        <option value ="7">JUL</option>
        <option value ="8">AUG</option>
        <option value ="9">SEP</option>
        <option value ="10">OCT</option>
        <option value ="11">NOV</option>
        <option value ="12">DEC</option>
        </select>
        <select name ="year">
        <option value ="1950">1950</option>
                <option value ="1951">1951</option>
                <option value ="1952">1952</option>
                <option value ="1953">1953</option>
                <option value ="1954">1954</option>
                <option value ="1955">1955</option>
                <option value ="1956">1956</option>
                <option value ="1957">1957</option>
                <option value ="1958">1958</option>
                <option value ="1959">1959</option>
                <option value ="1960">1960</option>
                <option value ="1961">1961</option>
                <option value ="1962">1962</option>
                <option value ="1963">1963</option>
                <option value ="1964">1964</option>
                <option value ="1965">1965</option>
                <option value ="1966">1966</option>
                <option value ="1967">1967</option>
                <option value ="1968">1968</option>
                <option value ="1969">1969</option>
                <option value ="1970">1970</option>
                <option value ="1971">1971</option>
                <option value ="1972">1972</option>
                <option value ="1973">1973</option>
                <option value ="1974">1974</option>
                <option value ="1975">1975</option>
                <option value ="1976">1976</option>
                <option value ="1977">1977</option>
                <option value ="1978">1978</option>
        <option value ="1979">1979</option>
        <option value ="1980">1980</option>
        <option value ="1981">1981</option>
        <option value ="1982">1982</option>
        <option value ="1983">1983</option>
        <option value ="1984">1984</option>
        <option value ="1985">1985</option>
        <option value ="1986">1986</option>
        <option value ="1987">1987</option>
        <option value ="1988">1988</option>
        <option value ="1989">1989</option>
        <option value ="1990">1990</option>
        </select>
        </td>
</tr>

<!--comments: To display customer address field-->

<tr>
    <td>Address<span class="mandatory">*</span></td>
    <td>
        <textarea rows="5" cols="20" name="addr" maxlength="50"></textarea>
    </td>
</tr>

<tr>
    <td>City<span class="mandatory">*</span></td><td><input type="text" name="city" maxlength="25" onKeyUp="validateCity();" onBlur="validateCity();"><label id="message4"></label></td>

</tr>

<tr>
    <td>State<span class="mandatory">*</span></td><td><input type="text" name="state" maxlength="25" onKeyUp="validateState();" onBlur="validateState();"><label id="message5"></label></td>

</tr>

<tr>
    <td>PIN<span class="mandatory">*</span></td><td><input type="text" name="pinno" maxlength="6" onKeyUp="validatePIN();" onBlur="validatePIN();"><label id="message6"></label></td>
</tr>

<!--comments: To display customer telephone number field-->

<tr>
    <td>Telephone Number<span></span></td><td><input type="text" name="telephoneno" maxlength="15" onKeyUp="validateTelephone();" onBlur="validateTelephone();"><label id="message7"></label></td>
</tr>

<!--comments: To display customer email id field-->

<tr>
    <td>E-mail<span class="mandatory">*</span></td><td><input type="text" name="emailid" maxlength="30" onKeyUp="validateEmail();" onBlur="validateEmail();"><label id="message9"></label></td>
</tr>

<tr>
    <td>User Id<span class="mandatory">*</span></td><td><input type="text" name="uid" maxlength="30" onKeyUp="validateuserid();" onBlur="validateuserid();"><label id="message23"></label></td>
</tr>

<!--comments: To display submit and reset buttons-->
<tr>
        <td><span class="mandatory">*<font size="3"><b> mandatory fields</b></font></span></td>
        <td><input type="submit" value="Submit" name="sub"/>
        <input type ="reset" value ="Reset" name ="res"></td>
</tr>

</form>

</table>

Infy银行
添加新客户
客户名称*
性别*
男性的
女性的
出生日期*
1.
2.
3.
4.
5.
6.
7.
8.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
简
功能电子块
破坏
四月
也许
六月
七月
AUG突击步枪
九月
十月
十一月
十二月
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
地址*
城市*
陈述*
别针*
电话号码
电子邮件*
用户Id*
*必填字段

我已经在javascript函数中为所有字段编写了代码。如果所有字段都为空，那么我必须对此发出警告。但每次警报都会出现

下面是javascript代码

function validateall(dis)
{
 var lbl=document.getElementsByTagName('label');
 var imax=7;
 for(var i=0;i<=imax;i++)
 {
  //var j=i-1;
  var v=lbl[i].getAttribute("id");
  var x=document.getElementById(v).style.visibility;
  if(x=="hidden" && i==lbl.length)
  {
   return true;
  }
  else{
   alert("please fill * fields");
   return false;
  }
 }
}

功能验证全部（dis）
{
var lbl=document.getElementsByTagName（'label'）；
var-imax=7；
对于（var i=0；i而言，问题在于

x=="hidden" condition. 


始终将
x
返回到
”
，因为您尚未将
标签的可见性设置为隐藏

因此，
if（x==“hidden”&&i==lbl.length）
条件失败，并且总是转到else块。
这是什么意思？但警报始终出现。如果for循环结束，则可以说如果ilbl[i]中
，您不需要按ID查找。在Javascript中，您在哪里检查字段是否为空？在循环的第一次运行时，您总是
返回
，因此您甚至从不检查其他元素。如果有人能告诉您投票被否决的原因，那就太好了。您是对的，默认情况下x=null。但我们已将此设置为隐藏，您可以在这里检查我在JSFIDLE中的所有代码-
var x = document.getElementById(v).style.visibility;