HTML 如何调用验证例程

How does the HTML call the validation routine?

本文关键字:验证 例程 调用 何调用 HTML      更新时间:2023-09-26

我有一些代码,我想知道是否有人能够帮助我,因为我不是 100% 确定它如何调用验证例程。我想我知道哪个部分这样做,但我不知道它实际上如何/做什么。也许有人可以在这里帮助我?三:

<html>
 <head>
  <title>Exam entry</title>
  <script language="javascript" type="text/javascript">
   function validateForm(){
     var result = true;
     var msg="";
     if (document.ExamEntry.name.value==""){
       msg+="You must enter your name 'n";
       document.ExamEntry.name.focus();
       document.getElementById('name').style.color="red";
       result = false;
     }
     if (document.ExamEntry.subject.value==""){
       msg+="You must enter the subject 'n";
       document.ExamEntry.subject.focus();
       document.getElementById('subject').style.color="red";
       result = false;
     }
     if(msg==""){
       return result;
     }
     else {
       alert(msg);
       return result;
     }
   }
  </script>
 </head>
 <body>
  <h1>Exam Entry Form</h1>
  <form name="ExamEntry" method="post" action="success.html">
   <table width="50%" border="0">
    <tr>
     <td id="name">Name</td>
     <td><input type="text" name="name" /></td>
    </tr>
    <tr>
     <td id="subject">Subject</td>
     <td><input type="text" name="subject" /></td>
    </tr>
    <tr>
     <td><input type="submit" name="Submit" value="Submit"   
          onclick="return validateForm();" /></td>
     <td><input type="reset" name="Reset" value="Reset" /></td>
    </tr>
   </table>
  </form>
 </body>
</html>

我认为它调用验证的行是这样的:

<form name="ExamEntry" method="post" action="success.html">

调用验证例程的行是这样的:

onclick="return validateForm();"

从字面上看,单击按钮时称为validateForm

No.它在此处调用验证(在提交按钮处):

<td><input type="submit" name="Submit" value="Submit"   
      onclick="return validateForm();" /></td>

看看提交按钮 - 你会发现对validateForm()的调用。

if (document.ExamEntry.subject.value==""){ msg+="You must enter the subject 'n"; document.ExamEntry.subject.focus(); document.getElementById('subject').style.color="red"; result = false;