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JavaScript in JSP

 
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Hello Friends,
Consider the following code:


<html>
<head>
<script language="javascript" >
function log2()
{
if(document.login2.cid.value=="")
{
alert("please enter your CID");
return false;
}

}
</script>
</head>

<body bgcolor="#6495ed" text="#000000">
<h1 align="center">Welcome</h1>
<form name="login2" method="POST" onSubmit="log2()"
action="login2.do" >
<br><br>
<center>CID : <input type="text" name="cid" size ="50"></center><br><br>
<center>Password : <input type="password" name ="pwd" size="30"></center><br><br>
<center>
<input type="submit" name="submit" value="Go" >
</center>
</form>

</body>
</html>

Here login2.do maps to a servlet Login2.java which checks for the validity of the user using Customer ID and password.
I�ve included javascript which alerts the user to enter the CID ,if the user clicks submit button without entering the CID.
But when I actually run the code without entering the CID value and then clicking the submit button ,an alert message is displayed and when I click on OK button of the alert message the request is sent to the servlet (Whereas I want the same page to be displayed so that the user is given another chance to enter CID and pwd)

Cheers,
Poonam.
 
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Not a JSP issue. Moved to the Javascript forum.
 
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You could try this:
<form name="login2" method="POST" onSubmit="log2(); return false;" action="login2.do" >
Good luck.
 
Poonam Kadu
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Hi Pablo,
It worked.Thanks a lot.But can you please explain me why did your code work.
cheers,
Poonam
 
Bear Bibeault
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Originally posted by Poonam Kadu:

It worked.Thanks a lot.But can you please explain me why did your code work.



The syntactic sugar of placing the Javascript code in the onsubmit attribute of the form element is really just a shorthand means of doling something like:



The routine value of the onsubmit handler must be false in order to prevent form submission.

So when you used:



your handler is:



Notice that there is no return for the handler. But if you were to write:



your handler is:



Thereby returning the value of the function log2() as the return value of the handler.

Clear as mud?
[ February 20, 2007: Message edited by: Bear Bibeault ]
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