XUL related queries

newbie in xul world

[kadnan]

hi All

This time i am with my queries about XUL development.I have read a couple of good articles but not clear about few things.

1)How can I intercept the signal when the user enters something in the address bar. I should be able to intercept it before the browser tries visiting the site.

2)I am getting unknown entity error for following code which is supposed to add a button in Browser toolbar

<?xml version="1.0"?>

<?xml-stylesheet type="text/css"
href="chrome://custombutton/content/sayhello.css"?>

<overlay
xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">

<script type="application/x-javascript"
src="chrome://sayhello/content/sayhello.js"/>

<toolbarpalette id="BrowserToolbarPalette">
<toolbarbutton id="sayhello-button" class="cHello"
label="&sayHello.label;" tooltiptext="&HiAdnan.tooltip;"/>
</toolbarpalette>

</overlay>

Thanks

[choster]

I am not familiar with XUL, but on the second point, you either need to define the entities &sayHello.label; and &HiAdnan.tooltip; or escape the ampersands, as &amp;sayHello.label; and &amp;HiAdnan.tooltip; in order for this to be valid XML.