function pop_center(mypage, myname, w, h, scroll,resizable) {
	var winl = (screen.width - w) / 2;
	var wint = (screen.height - h) / 2;
	var winprops = 'height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars='+scroll+',resizable='+resizable;
	win = window.open(mypage, myname, winprops)
	if ( parseInt(navigator.appVersion) >= 4 ) {
		win.window.focus();
	}
}