js判断是刷新还是关闭浏览器，js判断刷新页面，js判断关闭页面

window.onbeforeunload = onbeforeunload_handler;

window.onunload = onunload_handler;

 

function onbeforeunload_handler(){

　　var warning="确认退出?"; return warning;

}

function onunload_handler(){

　　var warning="谢谢光临"; alert(warning);

}