It looks like you are setting the value for the EmplID field in the insert form.
Normal practice would be for the ID field to be set in the database as an auto number field, and not assign a value for that field, let the database assign the value instead.
Is there a particular reason you are setting the value from the form?
Where you are setting the value, it seams the ID column is not set to auto number, so the:
function that looks the outnumber for the last inserted record is not setting the session properly.
you could use the form element in the redirect instead of the session, change:
$GoToPage = "employeecontact_view.php?EmplID=".($_SESSION['WADA_Insert_employeecontact']) ."";
$GoToPage = "employeecontact_view.php?EmplID=".((isset($_POST['EmplID']))?$_POST['EmplID']:'') ."";
but i think it would be better to set the EmplID column to outnumber and let the DB handle setting the ID value.