Take out the semicolons after the Values ie.,
$sql="INSERT INTO $tbl_name(VeteranName, Address, StateProv, ZipCode, Branch, Dateserved, Comments, guestname, Phonenumber, city)
VALUES('$VeteranName',
'$Address',
'$StateProv',
'$ZipCode',
'$Branch',
'$Dateserved',
'$Comments',
'$guestname',
'$Phonenumber',
$city')";
$result=mysql_query($sql);
Also, don't do $VeteranName = $_GET['VeteranName'];
etc.
just do extract($_REQUEST);