US Federal Income Tax calculator in javascript

fedtax.js

// Weekly Employee Income Withholding Calculator by GitHub#Liath
// Based on IRS Circular E - http://www.irs.gov/pub/irs-pdf/p15.pdf
// Per the "Percentage Method"
var  w = {
    s : {
        0    : { p : 0, s : 0 },
        71   : { p: 0.10, s: 0 },
        254  : { p: 0.12, s: 18.3 },
        815  : { p: 0.22, s: 85.62 },
        1658 : { p: 0.24, s: 271.08 },
        3100 : { p: 0.32, s: 617.16 },
        3917 : { p: 0.35, s: 878.6 },
        9687 : { p: 0.37, s: 2898.1 }
    },
    m : { // Married
        0    : { p : 0, s : 0 },
        222  : { p : 0.1, s : 0 },
        588  : { p : 0.12, s : 36.6 },
        1711 : { p : 0.22, s : 171.36 },
        3395 : { p : 0.24, s : 541.84 },
        6280 : { p : 0.32, s : 1234.24 },
        7914 : { p : 0.35, s : 1757.12 },
        11761 : { p : 0.37, s : 3103.57 }
    }
},
ba = 79.8,
c = function(m, a, g) { // Returns Federal Income Tax amount (Married, Allowances, Gross Income)
    g -= (ba*a); // Pay after allowances
    var b = Object.keys(w[(m==1) ? 'm' : 's']); //Married?
    for (var i = 0; i < b.length; i++) { // Find bracket
        if (b[i] > g)  {
            g -= b[i-1]; // Get taxable income
            b = w[(m==1) ? 'm' : 's'][b[i-1]]; // Set bracket
            return ((b.p*(g)) + b.s); // Taxable income * Tax Rate + Base Tax, per IRS Circular E table 5
        }
    }
}

typo, line 9: 7815 to 815
Thanks for the code and the update to it!