A chap that I know, asked me a question - it is shown below.

Hi Pete,

Hope you're well. I was hoping you could help me with 
the following small problem.

I have a web page with a text area that displays normal 
text: 

e.g. Hello Pete how are you

I'd like to be able to click a button on the form which 
opens a popup window where the user can type HTML.

e.g Hello <B>Pete</B> how are you.

When they close the window the text area on the calling 
web page display the actual text with the bold writing. 
I know it's something to do with innerHTML.

e.g. Hello Pete how are you.

Hope the above makes sense.

Pete.

The reply can be seen at PopUpInnerHTML.htm (only for Internet Explorer - can be easily be adapted for Netscape, but I was too lazy !!)
You can see the source by clicking on View -> Source

Hopefully it will help !!