var WindowObjectReference = null; //declare global variable

function openRequestedPopup ()
{
if(WindowObjectReference == null || WindowObjectReference.closed)
/*if pointer to the window object in memory doesn't exist or pointer exist but window is closed */
{
WindowObjectReference = window.open("http://www.shao-lin.net/medicalMassage.html",
"MedicalMassage","width=450,height=300,resizable,scrollbars=yes,status=yes");
/* creates the new window */
}
else
{
WindowObjectReference.focus ();
/* bring the new window on top with focus */
};
}