<script language="javascript">
<!--
var submitcount=0;
function disableSubmit()
{
if (typeof(Page_ClientValidate)=='function')
{
if (Page_ClientValidate() == true)
{
return checkSubmit();
}
else
{
return true;
}
}
else
{
return checkSubmit();
}
}
function checkSubmit()
{
if (submitcount == 0)
{
submitcount++; return true;
}
else
{
alert('This form has already been submitted.');
return false;
}
}
//-->
</script>