Run js inside UpdatePanel

We have a web page with an UpdatePanel (see sample below).  Inside the panel is a Button control that we want to have a JavaScript function run before the page is submitted but that does not work. I think it is due to the button being inside the panel but not sure how to make it work.

<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional"><ContentTemplate><table style="width: 90%; background-color: #CCCCCC"><tr><td class="center"><asp:Button ID="BtnCloseJob" runat="server" Text="Close This Job" 
                            Font-Bold="True" Font-Size="Medium" OnClientClick="btnDisable(this);" /></td><td class="center"><asp:Button ID="BtnCancel" runat="server" Text="Cancel Closing" ForeColor="Red" 
                            PostBackUrl="~/orders/OpenOrders.aspx" Font-Size="Medium" /></td><td class="center"><asp:Button ID="BtnScan" runat="server" Text="Scan Final Bill" 
                            Font-Size="Medium" PostBackUrl="~/Scan.aspx" /> </td></tr></table></ContentTemplate></asp:UpdatePanel>