I am developing a toolbar for a company. In that toolbar I have a
button that opens a dialog box. What I exactly want to do is get
information from a particular url ( without opening that url ) and
display it in my dialog box.

So basically, when the user clicks the dialogbox button on toolbar, it
recieves information from an other webpage and displays it in
dialogbox without opening that particular page. This information will
change everyday so users will get new information. I thought of
getElemenByTagName but I am not sure how to do it without visiting
that webpage.

I dont know if thats even possible.

I have to use firefox 3.0

Thanks in advance