I can use the following code to popup a MessageBox inside an Update Panel...
System.Web.UI.ScriptManager.RegisterClientScriptBlock(this.Page, typeof(Page), "myKey", "alert('ALERT MESSAGE!')", true);
The problem is that in Firefox none of my drop down boxes work after the message has gone. They appear but when I select an item it doesn't change. It seems to work fine in IE.
Any ideas how to fix this or perhaps another way of producing an alert in an UpdatePanel?