convert hex to decimal

hex2dec, dec2hex

function hex2dec(hex) {
	hex = hex.toLowerCase(hex).split('');
	var dec = 0;
	while(h = hex.shift()) {
		var code = h.charCodeAt(0);
		dec = dec << 4; 
		dec += code < 58 ? code - 48 : code - 87;
	}
	return dec;
}

function hex2dec(hex) {
    return parseInt(hex, 16);
}

function dec2hex(dec) {
	if(dec == 0) return "0";
	var hex = "";
	while(dec) {
		var b = dec & 0xf;
		hex = (b < 10 ? b : String.fromCharCode(b + 87)) + hex;
		dec = dec >> 4;
	}
	return hex;
}

function dec2hex(dec, padding) {
	var hex = "";
	if(dec == 0)  {
		hex = "0";
	} else {
		while(dec) {
			var b = dec & 0xf;
			hex = (b < 10 ? b : String.fromCharCode(b + 87)) + hex;
			dec = dec >> 4;
		}
	}
	var padder = "0000000000";
	return (padder + hex).substr(padder.length - padding + hex.length, padding);
}