Custom Error Handling

Is there any reason the following code should not work? I define the error function, then tell PHP to use it, then call a function which doesn't exist (test), and it will print the error on screen that that function doesn't exist, but it won't alert me, so it's obviously not entering the catchError function, why? <?php function catchError($num, $string, $file, $line) { echo "<script language=\"javascript\">alert('$num:$string:$file:$line');</script>"; } set_error_handler("catchError"); test(); ?> Thanks for your help, Adam Voigt adam.voigt@cryptocomm.com