var Utility = {

	isInteger: function (s) {
		return (s.toString().search(/^-?[0-9]+$/) == 0);
	},	
	
	removeAllChilds: function (node) {
		if (typeof node != "undefined") {
			if (node.hasChildNodes()) {
				while (node.childNodes.length >= 1) node.removeChild(node.firstChild);
			}
		}	
	},
	
	clone: function (obj) {
		if(obj == null || typeof(obj) != 'object') return obj;
		var temp = new obj.constructor(); // changed (twice)
		for(var key in obj) temp[key] = Utility.clone(obj[key]);
		return temp;
	}
};

function isInteger(s) {
	return (s.toString().search(/^-?[0-9]+$/) == 0);
}

function isUpper(s) {
	return (s.toUpperCase() == s);
}

function isLower(s) {
	return (s.toLowerCase() == s);
}

function abs(n) {
	if (n>=0) return n;
	else return n*(-1);
}