window.onload=function() {
	var crows=getElementsByClass(document,"crow","tr");
	for (var i in crows) {
		crows[i].onmouseover=function() {
			moveTooltip(this);
		}
		crows[i].onmouseout=function() {
			hideTooltip();
		}
	}
}

function getTooltip() {
	var ttdiv=document.getElementById("tooltip");
	if (ttdiv==undefined) {
		var ttdiv=document.createElement("div");
		ttdiv.id="tooltip";
		ttdiv.innerHTML="Hello world";
		document.body.appendChild(ttdiv);
	}
	return ttdiv;
}
function moveTooltip(tr) {
	var HEIGHT=220;
	var ttdiv=getTooltip();
	var pos=findPos(tr);
	var xpos=pos[0]+10;
	var ypos=pos[1]+tr.offsetHeight+10;
	ttdiv.style.left=xpos+"px";
	ttdiv.style.display="block";
	ttdiv.innerHTML=document.getElementById('tt'+tr.id).innerHTML;
	var img=ttdiv.getElementsByTagName("img")[0];
	img.src="pics/"+tr.id+".jpg";
	if (ypos+HEIGHT>(window.innerHeight+window.scrollY)) {
		//overlaps bottom
		if (pos[1]-10-HEIGHT>window.scrollY) {
			//space at top
			ypos=pos[1]-10-HEIGHT;
			ttdiv.style.top=ypos+"px";
		}
	}
	ttdiv.style.top=ypos+"px";
}
function hideTooltip() {
	var ttdiv=getTooltip();
	ttdiv.style.display="none";
}

function tooltipExists() {
	return ;
}

function getElementsByClass(node,searchClass,tag) {
  var classElements = new Array();
  var els = node.getElementsByTagName(tag);
  var elsLen = els.length;
  for (i = 0, j = 0; i < elsLen; i++) {
    if (els[i].className==searchClass) {
      classElements[j] = els[i];
      j++;
    }
  }
return classElements;
}

function findPos(obj) {
	var curleft = curtop = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}
	return [curleft,curtop];
}