Getting Form elements in JavaScript

[bharadwajrv]

Hi,
i wanted to validate the Form elements using Java Script here is my code but it not working validating...

In script
function ValidateNewPost()
{
if (document.NewPost.txtSubject.Length ==0 )
{
alert("Enter the Subject");
return false;
}
}

in body
<form OnSubmit="ValidateNewPost();" name=NewPost>

<input type=text name=txtSubject>
..
</form>


thanks in adv.
Venu Bharadwaj

[Zvona]

function ValidateNewPost()
{
if (document.NewPost.txtSubject.value.length ==0)
{
alert("Enter the Subject");
return false;
}
}

in body
<form onsubmit="return ValidateNewPost();" name="NewPost">
<input type="text" name="txtSubject">
</form>

[websmith99]

A few points:

If your form elements have dynamic names (filled in server side) and there is the possibility that a name could contain spaces, then it is best to use the forms[] and elements[] collections when using the DOM to reference them.

Example in valid XHTML:

<input type="text" name="<%= textField1 %>" />

evaluates to:

<input type="text" name="my textfield" />


Now using

document.NewPost.my textfield.value.length

will result in a JavaScript error, as the DOM reference is truncated at the space between the "y" and the "t" in "my textfield". The solution as mentioned above would be to do this:

document.forms['NewPost'].elements['my textfield'].value.length


Secondly, if the condition in ValidateNewPost() fails, you should explicitly return true, as the onsubmit event handler expects a return value from the function and not all browsers would return a value implicitly in that case:

if (document.forms['NewPost'].elements['my textfield'].value.length==0) {
alert("Enter the Subject");
return false;
} else {
return true;
}


:cool: