Using Close Window Buttons On A Refreshed Page

I'm new to javascript and im trying to add a close button function to my certain pages of my site. I use this code:

<a href='javascript:window.close();'>Close Window</a>

to create a hyperlink which closes the window. However with pages which
display data retrieved from a database using PHP i use a form to submit
a search on the page which displays results. At the bottom of the page
is the close window link, however it fails to work once a form has been
submitted on the page. It only works when the page first loads.

Any ideas guys on how i can get a close window option that works on my
results page after submitting a search?