日历扩展程序不起作用

I am using calender extender in my project. But there is some problem in the design of calender extender.

Below is my code and the output design i got.

<td align="right">
                From Date:
                 <asp:TextBox ID="txtDocStartDate" runat="server" CssClass="TextBox100" ></asp:TextBox>
                    <asp:CalendarExtender ID="CaltxtDocStart" runat="server" TargetControlID="txtDocStartDate">
                    </asp:CalendarExtender>
 </td>

Design:

enter image description here

What may be the problem i am not getting proper design?

May be it's because of you have not applied cssClass for calendar control.

check out this and apply proper css for calendar control

http://www.ezineasp.net/post/ASP-Net-Custom-Calendar-Control-using-CSS-styles.aspx