var newWin = null;

function winpopup(url, windowname, width, height, scroll)
{
	if(newWin != null && !newWin.closed)
    {
        newWin.close();
    }
	newWin = window.open(url,windowname,"location=0,menubar=0,toolbar=0,hotkeys=no,scrollbars="+ scroll +",resizable=no,personalbar=0,status=0,left="+ (((screen.availWidth)/2)-(width/2)) +",top="+ (((screen.availHeight)/2)-(height/2)) +",width="+ width +",height="+ height);
	//newWin.focus();
}