var popwin=null;
var str;

function isnasos(url,w,h)
{

  ClosePopWindow();

popwin = window.open(url,"langas",'width=' + w + ',height=' + h + ',resizable=0,scrollbars=0,menubar=no,top=20,left=0');

}

  function ClosePopWindow() 
{
  if ( popwin!=null && popwin.open ) popwin.close(); 
  popwin=null; 
}