Ok, you got a form and you submit it to lets say validate.php. In that file you make your checks and stuff and when it fails, redirect it back to the form.
if($issue=="" || $impact=="" || $starttime=="" || $endtime=="" || $workaround=="" || $resolution=="" || $ticket=="" || $contact=="")
{
header("Location:http://www.yoursite.com/form.php?err=1");
}
else {
// Do your stuff, mail your form or whatever
}
Ok, if validation fails, it sends you back to the form with a variable $_GET['err'] which is 1. Now all you have to do is put that echo somewhere in your form.php to inform user that there was a problem.
if ($_GET['err']==1)
{
echo "Please fill out every field!";
}