First in your main.html or index.html file you must state the name of the frame along with the file src so:
<frame src="header.html" name="header">
Then when you want to make a link in the main frame that puts a page in the header frame you must put a target in the link like this:
<a href="page.html" target="header">Click Here</a>
See. You can do the same thing with other frames too. Just remember to name the frame and express a target frame in the link. Tell me how it goes.