function getStyle(el,style)
{
	if(typeof el == "string")
		var element = document.getElementById(el);
	else
		var element = el;
	if (element.currentStyle)
		var value = element.currentStyle[style];
	else if (window.getComputedStyle)
		var value = document.defaultView.getComputedStyle(element,null).getPropertyValue(style);
	return value;
}


function getposOffset(overlay, offsettype){
   var totaloffset=(offsettype=='left')? overlay.offsetLeft : overlay.offsetTop;
   var parentEl=overlay.offsetParent;
   while (parentEl!=null) {
      if(getStyle(parentEl, "position") != "relative"){
	     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('right')!=-1)? (curobj.offsetWidth) : -(subobj.offsetWidth-curobj.offsetWidth)) ;
      var ypos=getposOffset(curobj, 'top')+((typeof opt_position!='undefined' && opt_position.indexOf('bottom')!=-1)? curobj.offsetHeight : -(subobj.offsetHeight));
     
	  subobj.style.left=xpos+'px';
      subobj.style.top=ypos+'px';
      return false;
   }
   else{
   return true;
   }
}


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