isEven function for javascript

gistfile1.js

// efficient isEven function
// you can insert a number or a string, doesn't matter
// it doesn't take numbers after the dot into account because noone uses them anyways
// it's also very handy for shopping websites because you can do
// isEven("$ 31.00") and it will say 'not even'.
// or isEven("32.00 $") and will say 'even'
function isEven(a) {
    a = a.toString().replace(/[^0-9.]/g, "");
    var stack = [];
    var rev = a.split('').reverse();
    for (var ix = 0; ix < rev.length; ix++) {
        if (rev[ix] == ".") stack.push("dot")
        else if (rev[ix] == "1" || rev[ix] == "3" || rev[ix] =="5" || rev[ix] == "7" || rev[ix] == "9")
           stack.push("odd")
        else
           stack.push('even')
    }
    var wholenumber = stack.splice(stack.indexOf("dot") + 1)
    return wholenumber[0] == "even";
}