Worksheet Activate Event Question

I wrote a worksheet activate event (for wrksht1). It reads a list of customer inputs found on wrksht1 then parses these inputs into 'like' lists and pastes the results into a wrksht called ADIM. ADMIN is kept well hidden so our customer cannot mess with it. These parsed lists are then used as validation data with the drop down menus applied to cells found on wrksht2. So to recap, inputs on wrksht1 appear as drop down values for cells found on wrksht2. Here's the problem. The worksheet activate event is triggered whenever wrksht1 is activated and since the code changing the focus away from this wrksht and then back to it, it appears to enter an endless loop. At least I think that is what is happening. Is there a way to programmatically deactivate the event so that when focus returns to wrksht1 the event does not trigger and cause an endless loop? and then reactivate so the event triggers then next time the user changes focus.