How do you delay a Pop Up window

What i am trying to do is create a page where the window.open will delay for 30 seconds before opening the popup.
And also with the window.close will then close 15 seconds after the window pops up.
Is there any help from anyone on this.
For whatever reason i cant figure it out.
Thankyou for you help

To creata a delay in javascript:

setTimeout (string expression, int milliseconds);

e.g.

function pop() {
//code goes here
}

setTimeout ("pop()", 30000);