Convert a number to an amount

gistfile1.js

Number.prototype.toAmount = function() {
	var parts=(this+'').split('.');
	parts[0]=(parts[0]?parts[0]:'0');
	parts[1]=(parts[1]?parts[1].substring(0,2):'00');
	parts[1]+=(parts[1].length==1?'0':'');
	return parts[0]+'.'+parts[1];
	}

var price=12.112;
console.log(price.toAmount()); // Outputs 12.11

var price=12.12;
console.log(price.toAmount()); // Outputs 12.12

var price=12.1;
console.log(price.toAmount()); // Outputs 12.10

var price=0.1;
console.log(price.toAmount()); // Outputs 0.10

var price=0;
console.log(price.toAmount()); // Outputs 0.00

var price=-0.1;
console.log(price.toAmount()); // Outputs -0.10