function addEvent(obj, evType, fn) { 
	if (obj.addEventListener) { 
		obj.addEventListener(evType, fn, false); 
		return true; 
	} else if (obj.attachEvent)	{ 
		var r = obj.attachEvent("on"+evType, fn); 
		return r; 
	} else { 
		return false; 
	} 
}
/*
function $(strId){
	return document.getElementById(strId);
}
*/
function getElementsByClassName(oElm, strTagName, strClassName){
	var arrElements = (strTagName == "*" && oElm.all)? oElm.all : oElm.getElementsByTagName(strTagName);
	var arrReturnElements = new Array();
	strClassName = strClassName.replace(/\-/g, "\\-");
	var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$)");
	var oElement;
	for(var i=0; i<arrElements.length; i++){
		oElement = arrElements[i];		
		if(oRegExp.test(oElement.className)){
			arrReturnElements.push(oElement);
		}	
	}
	return (arrReturnElements)
}

function tab_klikk(num)
{
	for(var i=0; i < tab_linkek.length; i++) {
		document.getElementById(tab_linkek[i]).className = "";	
	}
	for(var i=0; i < tab_lapok.length; i++) {
		document.getElementById(tab_lapok[i]).style.display = "none";
	}

	document.getElementById("tab-link-"+num).className = "sel";	
	document.getElementById("tab-lap-"+num).style.display = "block";
}