AJAX postback problems

[SAL]

Hello,
I have a GridView control with two template fields. The first template field
has a linkbutton. The second has a panel control with an update panel inside
it with another gridview inside of that. I have a PopupExtender in this
template field as well and when the user clicks the link button in the first
template field, the child gridview pops up with the child records showing in
this gridview.
I have two problems with this.

In this child gridview there are two template fields that have check boxes
in them. When one of the checkboxes is clicked, code behind runs to do a
check in the database. This hides the popup again. How to keep the popup
showing until I want it to be hidden again?

I'll cover the second issue in another post.

Thanks for any help

SAL