Make a question if you change a page
<p>i'm new to starckoverflow.</p>

<p>I'm trying to stop to change the current page. I have an order page, with a lot of field that are updated on line.
I would like to make a question if your move to previous page, or if you click any other url, so i can show something like :
Attention  !!! if you continue you will lost all data already inserted.</p>

<p>So i can erase all data already inserted in db.
Is possible to do this ?</p>

<p>I'm working with aspx page in VB
Thanks to all
Alex</p>
