want to number of days from 2 date selections??

hi,

I have 2 asp.net calender controls as below -
1, Assignment Start date
2, Assignent End date

The user can make selections and in the final Textbox I want the
number of days between the two dates to show up - after calender selections without
the user being able to manually type the days







<legend style="border: 1px none #FFFF99; color: #000"> <b>SCHEDULE</b></legend>      START DATE <asp:textbox runat="server" ID="StartDate" CssClass="TextBox" Width="180px"></asp:textbox>      <br />     <asp:Label ID="Label3" runat="server" Text="Label" Font-Size="Small" ForeColor="#333333" >click ico ...