/* 
 * Javascript object extensions
 */
String.prototype.format = function() {
	var pattern = /\{\d+\}/g;
	var args = arguments;
	return this.replace(pattern, function(capture) {return args[capture.match(/\d+/)]; });
}
String.prototype.isEmail = function() {
    var reEmail = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
    return reEmail.test(this);
}