HI SoftwareMaker,
You dont really have to use input button, you can use submit button to do your validation.

this is how i do my validation on most forms

Code:
<html>
<head>
<script>
function validate()
{
   if (some condition)
   {
    alert(msg);
    return false;
    }

    if (another condition)
    {
    alert (msg);
    return false;

return true; 
//if the functions returns true then the form will 
//be submited otherwise the form wont be submited
}
 </script>
<body>

<form action="submit.asp" onsubmit="return validate()">

</form>
</body>
</html>
Hope this helps
Danial