Below are 13 different ways to close a window with javascript. They include a text link, image link and a form button.
In case you're thinking of doing something sneaky with the onmouseover versions, forget it. Almost all browsers ask the user if they want to close the window before it happens.
To close a normal window use this action "javascript:window.close()".
To close a framed window use this action "javascript:top.window.close()".