script for textbox

Question

hi

 <script type="text/javascript">

        function MouseUptxtarea(obj) {

            document.getElementById('<%=txtArea.ClientID %>').focus();

        }

    </script>

 <asp:TextBox ID="txtWhat" runat="server" CssClass="input_bar" OnTextChanged="txtWhat_TextChanged"

                                TabIndex="2"  onblur="MouseUptxtarea() OnClick="return validate()"></asp:TextBox>

                        

                            <ajaxToolkit:TextBoxWatermarkExtender ID="TextBoxWatermarkExtender3" runat="server"

                                TargetControlID="txtWhat" WatermarkText="eg : Restaurants, Hotels, Pubs ?" WatermarkCssClass="watermark_what" />

                        </li>

                        <li class="where">Where in

                            <asp:Label ID="lblTitle" runat="server" />

                         

                            <asp:TextBox ID="txtArea" runat="server" CssClass="input_bar" OnTextChanged="txtArea_TextChanged"

                                TabIndex="3" />
by using that script it works in google chrome but when i run the application in ie it goes to next textbox why?
please help me