function openPopup(url,title){
	
	setOpacity($("modal_background"),40);
	
	$("modal_window").style.visibility="visible";
	$("modal_background").style.display="block";
	
	ajaxPage(url,"modal_content");
	addEvent($("modal_background"),"click",closePopup);
}

function closePopup(){
	$("modal_window").style.visibility="hidden";
	$("modal_background").style.display="none";
	$("modal_content").innerHTML="";
	removeEvent($("modal_background"),"click",closePopup);
}


function openIllustration(url){
	ajaxPage(url,"modal_slide_content");
	slide($('modal_slide'),$('modal_slide_content'),'down',20);
}

function closeIllustration(){
	slide($('modal_slide'),$('modal_slide_content'),'up',20);
}