function centerPOP(w,h,url,name, opt){
var there = null;
	if(window.screen){
		var hor = screen.availWidth;
		var ver = screen.availHeight;
		there = window.open(url,name,'width=' + w + ',height=' + h + ',left=' + ((hor - w - 10) * .5) + ',top=' + ((ver - h -30) * .5) + ',scrollbars=' + opt + ',');
	}
}