/**
* Formats the number according to the 'format' string; adherses to the american number standard where a comma is inserted after every 3 digits.
*  note: there should be only 1 contiguous number in the format, where a number consists of digits, period, and commas
*        any other characters can be wrapped around this number, including '$', '%', or text
*        examples (123456.789):
*          '0' - (123456) show only digits, no precision
*          '0.00' - (123456.78) show only digits, 2 precision
*          '0.0000' - (123456.7890) show only digits, 4 precision
*          '0,000' - (123,456) show comma and digits, no precision
*          '0,000.00' - (123,456.78) show comma and digits, 2 precision
*          '0,0.00' - (123,456.78) shortcut method, show comma and digits, 2 precision
*
* @method format
* @param format {string} the way you would like to format this text
* @return {string} the formatted number
* @public
*/

Number.prototype.format = function(format) {
    var hasComma = -1 < format.indexOf(','),
		psplit = format.replace(/[^0-9\.]/g, "").split('.'),
		that = this;

    // compute precision
    if (1 < psplit.length) {
        // fix number precision
        that = that.toFixed(psplit[1].length);
    }
    // error: too many periods
    else if (2 < psplit.length) {
        throw ('NumberFormatException: invalid format, formats should have no more than 1 period: ' + format);
    }
    // remove precision
    else {
        that = that.toFixed(0);
    } // get the string now that precision is correct
    var fnum = that.toString();

    // format has comma, then compute commas
    if (hasComma) {
        // remove precision for computation
        psplit = fnum.split('.');

        var cnum = psplit[0],
			parr = [],
			j = cnum.length,
			m = Math.floor(j / 3),
			n = cnum.length % 3 || 3; // n cannot be ZERO or causes infinite loop

        // break the number into chunks of 3 digits; first chunk may be less than 3
        for (var i = 0; i < j; i += n) {
            if (i != 0) { n = 3; }
            parr[parr.length] = cnum.substr(i, n);
            m -= 1;
        }

        // put chunks back together, separated by comma
        fnum = parr.join(',');

        // add the precision back in
        if (psplit[1]) { fnum += '.' + psplit[1]; }
    }

    // replace the number portion of the format with fnum
    return format.replace(/[\d,?\.?]+/, fnum);
}