// JavaScript Document
function toggle_visibility(id,img_name,img_src) {
	var e = document.getElementById(id);
    	if(e.style.display == 'block') {
			e.style.display = 'none';
			document[img_name].src = "_images/" + img_src + "-1.jpg";
			}
		else {
        	e.style.display = 'block';
			document[img_name].src = "_images/" + img_src + "-2.jpg";
			}
	}
function arrow_down() {
	var imagelink = document.getElementById("image-link");
	imagelink.setAttribute("onmouseover","return document['arrow'].src = '_images/arrow-down.jpg';");
	imagelink.setAttribute("onmouseout","return document['arrow'].src = '_images/arrow.jpg';");
	}
function topowanie() { document.getElementById("top").style.display="none"; }