I'm not sure that what you are asking is primarily a PHP issue. Here is a quick example of frameset navigation. Copy and paste the 4 files and name as indicated and then launch f1.htm. Hope this helps.
CALL THIS f1.htm
<html><head><title>Frameset</title></head>
<frameset cols="200,*" frameborder=0 border=0>
<frame src="c1.htm" name="LEFT" scrolling="no">
<frame src="c2.htm" name="RIGHT" scrolling="no">
</frameset></html>
NAME THIS c1.htm
<html><head><title>Column 1</title>
<style>body {color:black; background:silver}</style>
</head><body><div align=center>C1</div></body></html>
NAME THIS c2.htm
<html><head><title>Column 2</title>
<style>body {color:black; background:yellow}</style>
</head><body><div align=center>
C2<br /><br /><a href="c3.htm" target="LEFT"
onClick='window.self.location="c4.htm"'>
CHANGE FRAMES</a>
</div></body></html>
NAME THIS c3.htm
<html><head><title>Column 3</title>
<style>body {color:black; background:blue}</style>
</head><body><div align=center>C3</div></body></html>
NAME THIS c4.htm
<html><head><title>Column 4</title>
<style>body {color:black; background:green}</style>
</head><body><div align=center>C4</div></body></html>
Clive