AJAX Tab Control problem on asp.net form

hello good people,
i have created atab control and added a gridview in it. When i run it this is how it shows:

i have tried adjusting the heights and widths of both but tono avail. here is my code:

<ajaxToolkit:TabContainer ID="TabContainer1" runat="server" ActiveTabIndex="0" 
                        Height="421px" style="z-index: 1; left: 212px; top: 271px; position: absolute" 
                        Width="933px">
                        <ajaxToolkit:TabPanel ID="TabPanel1" runat="server" HeaderText="Neurology">
                            <ContentTemplate>
                                <asp:GridView ID="GridView1" runat="server" AllowSorting="True" 
                                    AutoGenerateColumns="False" DataSourceID="Neuro" 

                                    style="z-index: 1; left: 242px; top: 367px; position: absolute; height: 309px; width: 870px">
                                    <Columns>
                                        <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
                                        <asp:BoundField DataField="Designation" HeaderText="Designation" 
                                            SortExpression="Designation" />
                                        <asp:BoundField DataField="Qualification" HeaderText="Qualification" 
                                            SortExpression="Qualification" />
                                        <asp:BoundField DataField="Shift" HeaderText="Shift" SortExpression="Shift" />
                                        <asp:BoundField DataField="Appointment_Timings" 
                                            HeaderText="Appointment_Timings" SortExpression="Appointment_Timings" />
                                    </Columns>
                                </asp:GridView>
                                <asp:SqlDataSource ID="Neuro" runat="server" 
                                    ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 
                                    SelectCommand="SELECT * FROM [Neurology]"></asp:SqlDataSource>
                            </ContentTemplate>
                        </ajaxToolkit:TabPanel>
                        <ajaxToolkit:TabPanel ID="TabPanel2" runat="server" HeaderText="Cardiology">
                        </ajaxToolkit:TabPanel>
                        <ajaxToolkit:TabPanel ID="TabPanel3" runat="server" HeaderText="Dermatology">
                        </ajaxToolkit:TabPanel>
                        <ajaxToolkit:TabPanel ID="TabPanel4" runat="server" HeaderText="Opthalmology">
                        </ajaxToolkit:TabPanel>
                    </ajaxToolkit:TabContainer>

Help needed ASAP please!