HTMLElement.prototype.hasClassName = function(className) {
	var classes= this.className.split(' ');
	return (classes.indexOf(className) != -1) ? true : false;
}

HTMLElement.prototype.addClassName = function(className) {
	className = className.trim();
	if (className != '' && !this.hasClassName(className)) {
		this.className += (this.className ? ' ' : '') + className;
	}
}

HTMLElement.prototype.removeClassName = function(className) {
	className = className.trim();
	var classes= this.className.split(' ');
	var idx= classes.indexOf(className);
	if (idx != -1) {
		classes.splice(idx, 1);
		this.className = classes.join(' ');
	}
}

String.prototype.trim = function() {
	return this.replace(/^\s+/, '').replace(/\s+$/, '');
};

String.prototype.ltrim = function() {
	return this.replace(/^\s+/, '');
};

String.prototype.rtrim = function() {
	return this.replace(/\s+$/, '');
};

function NX() {
};
NX = new NX;