function processNumber(inputField) {
try {
var inpVal = parseInt(inputField.value, 10);
if (isNaN(inpVal)) {
var msg = "Please enter a number only.";
var err = new Error(msg);
if (!err.message) {
err.message = msg;
}
throw err;
}
} catch (e) {
alert(e.message);
inputField.focus();
inputField.select();
}
}