<%@ Register assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagprefix="AjaxToolKit" %>
<asp:TextBox ID="txtRecordTime" runat="server" cssclass="style" width="90px"></asp:TextBox>
<AjaxToolKit:CalendarExtender ID="txtRecordTime_CalendarExtender" runat="server" Enabled="True" TargetControlID="txtRecordTime" Format="yyyy-MM-dd" >
</AjaxToolKit:CalendarExtender>

<style type="text/css">
.style{width:250px;height:21px;line-height:21px;border:1px solid #7f9db9;}
</style>