function $(nodeId)
{
	var node = document.getElementById(nodeId);
	if (node){ return node; }
	else { return false; }
}

this.registerEvent = function() {

	this.isSetId = function(name) {
		if (document.getElementById(name) == null || document.getElementById == 'undefined') { return false; }
		else return true;
	}

	this.start = function() {
		var baseNode = document.getElementById("main_menu");
		var divNode = baseNode.getElementsByTagName("li");
		for (i=0; i<divNode.length; i++)
		{
			divNode[i].onmouseover = function(){ over(this); }
			divNode[i].onmouseout = function(){ out(this); }
		}
	}
	this.over = function(obj) {
		if ( obj.className != 'active' ) obj.className = 'selected';
	}
	this.out = function(obj) {
		if ( obj.className != 'active' ) obj.className = '';
	}

	if ( isSetId("main_menu") ) { start(); }
};
window.onload = registerEvent;


function addNum(nod)
{
  var current;
	current = parseInt(document.getElementById(nod).value);
	document.getElementById(nod).value = current + 1;
}

function deletNum(nod)
{
	var current;
	current = parseInt(document.getElementById(nod).value);
	if (current > 1){
		document.getElementById(nod).value = current - 1;
	}
}