javascript if number greater than number

I have this javascript function to validate if a number is greater than another number

function validateForm() {
    var x = document.forms["frmOrder"]["txtTotal"].value;
    var y = document.forms["frmOrder"]["totalpoints"].value;

    if (x > y) {
        alert("Sorry, you don't have enough points");
        return false;
    }
}

It's not working for some reason.

If I do alert(x) I get 1300, and alert(y) gives 999

This works....

function validateForm() {
    var x = 1300;
    var y = 999;

    if (x > y) {
        alert("Sorry, you don't have enough points");
        return false;
    }
}