function showPage(aSource)
{
 closePage();
 P1=window.open("http://" + aSource,"blank", "width=800, height=480, dependent=yes resizable=yes location=yes menubar=yes toolbar=yes scrollbars=yes left=200 top=50");  
}

function closePage()
{
 try{P1.close();}catch(e){}finally{}
}