JS检测浏览器弹出窗口是否被屏蔽

var blocked = false;

try {
 var wroxWin = window.open("http://www.wrox.com", "_blank");
 if (wroxWin == null){
 blocked = true;
 }
} catch (ex){
 blocked = true;
}
if (blocked){
 alert("The popup was blocked!");
}