a

The reason it opened in here is because the space in the original frame was given a NAME - then it was sent to open in that NAME

This is done by changing the code in the Table of Contents page

eg.

<UL>
<LI>
<B><FONT FACE="ARIAL"><FONT SIZE=+0><A HREF="a.html" TARGET="mainpage">page
A</A></FONT></FONT></B></LI>

<LI>
<B><FONT FACE="ARIAL"><FONT SIZE=+0><A HREF="b.html" TARGET="mainpage">page
B</A></FONT></FONT></B></LI>

<LI>
<B><FONT FACE="ARIAL"><FONT SIZE=+0><A HREF="c.html" TARGET="mainpage">page
C</A></FONT></FONT></B></LI>
</UL>