function getposOffset(overlay, offsettype){
var totaloffset=(offsettype=="left")? overlay.offsetLeft : overlay.offsetTop;
var parentEl=overlay.offsetParent;
while (parentEl!=null){
totaloffset=(offsettype=="left")? totaloffset+parentEl.offsetLeft : totaloffset+parentEl.offsetTop;
parentEl=parentEl.offsetParent;
}
return totaloffset;
}

function overlay(curobj, subobjstr, opt_position){
if (document.getElementById){
var subobj=document.getElementById(subobjstr)
subobj.style.display=(subobj.style.display!="block")? "block" : "none"
var xpos=getposOffset(curobj, "left")+((typeof opt_position!="undefined" && opt_position.indexOf("left")!=-1)? -(subobj.offsetWidth-curobj.offsetWidth) : 0) 
var ypos=getposOffset(curobj, "top")+((typeof opt_position!="undefined" && opt_position.indexOf("top")!=-1)? curobj.offsetHeight : 0)
/*LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
TopPosition = (screen.height) ? (screen.height-h)/2 : 0;*/
return false
}
else
return true
}

function overlayclose(subobj){
document.getElementById(subobj).style.display="none"
}