var windowPointer;

function wopen(wurl,wname,x,y,param) { 
   if(windowPointer)
     windowPointer.close();
   windowPointer=window.open(wurl,wname,'height='+y+',width='+x+ ',' + ((param) ? param : 'resizable=no,scrollbars=no,menubar=no,status=no'));
   windowPointer.focus(); 
}