打开外部链接时显示警告和超时。

I want that when a user clicks on any external link (identified by either particular id or class) on my site then he should get a popup with a counter of 10 seconds, after 10 seconds the popup should close and the user should be able to access the external URL. How can this be done? I'm able to show a warning like below but I don't know how to add timeout to it, also this is a I want that when a user clicks on any external