To make a window open to exact size, you must insert the following code in the <head> of your HTML document that contains the link to the HTML page for your Flash doc.

<script language="JavaScript">
function exactsize() {"name_of_flash_html_page.html","window _name","height=500,width=600,resizable=no");

You must change the "name_of_flash_html_page.html" to the name of the HTML document that contains your Flash movie. Make sure you include the path, or make sure that your 2 HTML pages are located in the same folder.
Change "window_name" to whatever you want to name the new window. Or youcan just leave it "window_name". Change the "height" and "width" to the dimensions of your Flash movie. for your link that connects to your Flash doc, write the following:

<a href="#" onClick="exactsize();">Whatever image or test you're using as a link</a>

Hope this helps!