When the mouse cursor is over the webpage

I would like to know how to tell when the mouse cursor is over the webpage form.
When it is not is when it is over the Internet browser controls, another webpage, the windows taskbar or desktop.
<script type="text/javascript"> $(document).ready(function () { $(".myform").mouseleave(function () { $("#<%= Button10.ClientID %>").trigger('click'); }); }); </script> <form runat="server" name="form1" class="myform"> <asp:Button ID="Button10" runat="server" Text="Logout" /> </form>