HTML表單驗證幫助

Question

我在創建一個簡單的HTML聯繫表單的過程中，我想驗證三個字段;姓名，電子郵件和消息。但是，我不是最聰明的，當涉及到JavaScript字段驗證，並希望得到一些幫助。我目前的形式是如下：

<form action="cgi-bin/FormMail.pl" method="post"> 
<input type="hidden" name="subject" value="From the feedback form" /> 
<input type="hidden" name="redirect" value="thankyou.html" /> 
<p>Whatever you want to say here</p> 
<p>&nbsp;</p> 
<table> 
<tr> 
<td align="left">Name:</td> 
<td><input type="text" name="name" size="30" value="" /></td> 
</tr> 
<tr> 
<td align="left">E-Mail:</td> 
<td><input type="text" name="email" size="30" value="" /></td> 
</tr> 
<tr> 
<td align="left">Content:</td> 
<td><textarea name="comment" cols="50" rows="5"></textarea></td> 
</tr> 
<tr> 
<td><input type="submit" value="Submit" /></td> 
<td></td> 
</tr> 
</table> 
<input type="hidden" name="redirect" value="thankyou.html" /> 
</form> 

Answer 1

，供大家參考：修改根據自己的需要

<script type="text/javascript"> 
function validateform() 
{ 
var x=document.forms["myForm"]["name"].value; 
if (x==null || x=="") 
    { 
    alert("Name Is Blank"); 
    return false; 
    } 

var x=document.forms["myForm"]["email"].value; 
var atpos=x.indexOf("@"); 
var dotpos=x.lastIndexOf("."); 
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length) 
    { 
    alert("invalid e-mail address"); 
    return false; 
    } 

var x=document.forms["myForm"]["comment"].value; 
if (x==null || x=="") 
    { 
    alert("Comment is blank"); 
    return false; 
    } 
} 
</script> 


<form name="myForm" action="cgi-bin/FormMail.pl" method="post" onsubmit="return validateform()"> 
<input type="hidden" name="subject" value="From the feedback form" /> 
<input type="hidden" name="redirect" value="thankyou.html" /> 
<p>Whatever you want to say here</p> 
<p>&nbsp;</p> 
<table> 
<tr> 
<td align="left">Name:</td> 
<td><input type="text" name="name" size="30" value="" /></td> 
</tr> 
<tr> 
<td align="left">E-Mail:</td> 
<td><input type="text" name="email" size="30" value="" /></td> 
</tr> 
<tr> 
<td align="left">Content:</td> 
<td><textarea name="comment" cols="50" rows="5"></textarea></td> 
</tr> 
<tr> 
<td><input type="submit" value="Submit" /></td> 
<td></td> 
</tr> 
</table> 
<input type="hidden" name="redirect" value="thankyou.html" /> 
</form>