PHP procedure call, not getting return parm

I'm ALMOST THERE!!!!

I can pass in my Customer number,
get the procedure called, the program does run,
but I don't get anything back!!!

What am I missing?

if (isset ($_POST["accountnum"])) {
$custnum = $_POST["accountnum"];
}
else{
$custnum=$_POST['distnum'];
}

$CustOut = ' ' ;
$sql = 'call PPROGLIB.Test_1 (?,?)' ;
$stmt = odbc_prepare($con, $sql) ;
print_r ($stmt) ;
$run = odbc_execute($stmt, array($custnum,$CustOut));
$CustName = $CustOut ;