Basic HTML trouble, need some help

[DanTHEGREAT]

This is my current website, starting out with HTML (from scratch)

Just wanted to do a basic one take a look:
http://cplusplus.netai.net/

I currently have two buttons,

Home and Lessons

I want so that when the user the Lessons, it goes to a different page (lessons.php)
and I want different text but the same header. (I know I just have to copy header and make new text file) but is there a way where I can make and If statement like this:

If user clicks Lessons, Then
Go to Lessons.php.

Also!
how can I make it so that the text in the middle on the homepage has a box around it, sort of like a middle background.

And finally last question. Take a look at my Hovering button codes, how come they do not work when I go to the real website??

<center><a href="http://cplusplus.netai.net/" onmouseover="document.images['s1a'].src='http://cplusplus.netai.net/button1hover.png';" onmouseout="document.images['s1a'].src='http://cplusplus.netai.net/button1.png';"><img src="http://cplusplus.netai.net/button1hover.png" name="s1a" height="47" width="176" alt="" border="0"></a><a href="http://cplusplus.netai.net/" onmouseover="document.images['s1a'].src='http://cplusplus.netai.net/button2hover.png';" onmouseout="document.images['s1a'].src='http://cplusplus.netai.net/button2.png';"><img src="http://cplusplus.netai.net/button2hover.png" name="s1a" height="47" width="176" alt="" border="0"></a></center>

Thanks, would appreciate the help!

--------------- Added [DATE]1290648027[/DATE] at [TIME]1290648027[/TIME] ---------------

anyone??

--------------- Added [DATE]1290689876[/DATE] at [TIME]1290689876[/TIME] ---------------

bump? Anyone?