Mark has addressed the issue in his documentation. I didn't read far enough. It says:
Alternatives to Using the OnBeforeUnload Event
The onbeforeunload is supported by Internet Explorer 6, Netscape 7.2 (not 7.1), and Firefox 1.0. The onbeforeunload event may not be the best solution for your particular needs. Another solution is to place the busybox.Show() method in the onclick event of the html elements (button, link etc.) that need to cause the busy box to appear. If the particular html tag does not have an onclick event, you can wrap your control in a span tag and use the onclick event of the span tag. I use this all the time.
Example:
<span onclick="busyBox.Show();">
<a href="anypage.htm">Any Page</a>
</span>
This allows you to specifically control which buttons and/or links cause the busy box to appear.
Another issue surfaced by users of the pervious version was the busy box appearing and remaining on the screen when a popup window was launched. This assumes your are using the onbeforeunload event, and you want to prevent the busy box from appearing. You can prevent this from happening by placing a "return false;" after the popup statement in your javascript event code.
Example:
<A onclick="window.open('anypage.htm'); return false;" href="#"> Open window</A>
The implementation has been surprisingly easy. I downloaded the server control for the busybox and found it to be a rather simple thing to use. Thanks a bunch to all who are/were involved in this little project. Our users will find this a very friendly addition to the intranet DNN project.
Ling