Verification on a text field for a form

any ideas for easy implementation?

[mikko]

I have a web site that relies on people filling out an application form, the main problem being that not everyone adheres to the '*' = required field and never fills the important parts which means the application cannot be processed.
Any one have any ideas on how to prevent this easily, i am not to technically minded outside html/javascript. Ideally something that when a person hits 'submit', a pop up message would tell the user they had not filled in the important fields.
Any suggestions/ideas/tutorials would be appreciated - honestly its driving me daft!
Thanks in advance

[gaston9x19]

I've tried several thins and looked around, strangely a seemingly simple concept doesn't want to work for me. I'd like to know also. Here's the gerneal idea, I think:

<script language="JavaScript">
<!--
function validate() {
if document.myForm.myText.value = '' {
alert('Form field blank!');
return false;
}
else
return true;
}
//-->
</script>

<form name="myForm" onSubmit="return validate()">
<input type="text" name="myText">
<input type="submit">
</form>

Can someone with a much better grasp of JS please help us on this one? I get a submission of the form no matter whether it's filled in or not, or just an "object expected" or "'(' expected" error, depending on how I modify it.

[gaston9x19]

Here's a bit more I found:

<form name=form action=address.asp method=post onsubmit="javascript:return ValidateForm(this)">

What the onsubmit method does here is waits for the results of the ValidateForm function. If it returns true, our validation has succeeded - the form entries are in an acceptable form. If it returns false, there has been an error, and the user will need to correct it before being allowed to submit the form. So now let's have a look at the ValidateForm function itself. Exactly how it will look of course will depend on the fields you need to validate.

This function can be used to check whether the user has entered anything in a given field. There are two possible types of 'emptiness' a form can return - a zero length string, or a null value. Here we simply check both these options, and return true if either of these are found to be true.

function IsEmpty(aTextField) {
if ((aTextField.value.length==0) ¦¦
(aTextField.value==null)) {
return true;
}
else { return false; }
}

function ValidateForm(form)
{
if(IsEmpty(form.aTextField))
{
alert('Form field blank!')
form.aTextField.focus();
return false;
}
return true;
}

To understand this function, remember that the return statement exits from the function and returns the code to the calling statement. Therefore, if the field 'IsEmpty', we alert the user, set the focus of the form to the appropriate field, and return false as the result. The calling statement reads the false value and does not submit the form. The user remains on the same page, with the focus pointing them to the error of their ways.

If however all the checks are verified, at the end of the ValidateForm function, we have a return true statement, meaning the form will submit successfully.

[mikko]

Thanks Gaston.
You are right, the on submit method is the way to go.
i have found in Dremweaver that if you create a form with various fields (in the past i would add behaviours to the fields individually) however if you select the form and then choose behaviours 'validate form' and choose what items you want validated, the end result is exactly as you say. The user hits submit and the fields that have not been filled in, a pop up message is given telling the user to fill in the space.
Thanks for the help!