var topWindow = null;

function closePopUp()
{ 
	if (topWindow == null)
		return;
	topWindow.close();
	topWindow = null;
}

function popup(puname,url,puw,puh)
{
  if (topWindow != null)
  {  
	  closePopUp();	  
  }
   	  
  var w = screen.availWidth   
  if (w > puw) {
	    var diffw = w - puw
	  	if (diffw > 20) { w = puw +20 }
	    }
	
  var h = screen.availHeight   
  if (h > puh) {
	    var diffh = h - puh
			if (diffh > 120) { h= puh +120 }
	   	}
	
  var options = "width=" + w + ",height=" + h + ",top=1,left=1,screenX=0,screenY=0,menubar=no,location=no,toolbar=no,status=no,'"
  topWindow = window.open(url,puname,options)
  topWindow.focus()
}