how can I create a html code that will automatically redirect someone to a different address without changing my url on top?

lets say... my website is google.com/crom.html

when users visit google.com I want it to redirect to google.com/crom.html but on the address bar it'll still say google.com

I think this is only possible with URL cloaking or URL hiding. More info here http://www.shoemoney.com/2008/02/12/...l-redirection/

I'm thinking of iframe.... anyone?

not just an iframe - ANY frame. just a frame will do. an iframe too.
pretty easy question.

you have the right answer already. just use it. surely if you try that out you'll soon see it works. what are you waiting for? or are you going to "move on"? (ha ha ha)

how would I code it using frames?

Well, you could do this:

<FRAMESET>
     <FRAME SRC="/crom.html">
</FRAMESET>

But I really wouldn't recommend it. It's overly complicated, and frames are not completely recognized by all browsers. And, there are lots of other ways to go about achieving this goal that have less code, and are widely recognized!
First off, you could use a php include:

PHP Code:

<?php include('crom.html'); ?>

Or even a server side include:

<!--#include virtual="/crom.html" -->

- Steve

Actually Frames are pretty much universally recognized by browsers. WHY you would want to use them, or cloak one URL to look like another, however, is beyond me.