function findPos(obj) {
var curleft = curtop = 0;
if (obj.offsetParent)
do {
curleft += obj.offsetLeft;
curtop += obj.offsetTop;
} while (obj = obj.offsetParent);
return [curleft,curtop];
}
function getRelCoordsParams(el, ev)
{
 var posx = 0;
var posy = 0;
if (!ev) var ev = window.event;
if (ev.pageX || ev.pageY) {
posx = ev.pageX;
posy = ev.pageY;
}
else if (ev.clientX || ev.clientY) {
posx = ev.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
posy = ev.clientY + document.body.scrollTop + document.documentElement.scrollTop;
}
 var elpos = findPos(el);
return '&x=' + (posx-elpos[0]) + '&y=' + (posy-elpos[1]);
}