Passing value from one textbox to another in ASP.Net Gridview
<p>I have two fields in the GridView
1. Notification Date
2. Effective Date</p>

<p>When user entered/change date in the Notification date, I would like to add 10 addtional  days in the Notification date value and auto populate in the effective date every time when user change the notification date. Please advise:</p>

<pre><code>&lt;asp:DetailsView ID="DetailsView1" runat="server" 
DataKeyNames="ID"
DataSourceID="ObjectDataSource1"
OnDataBound="DetailsView_OnDataBound"&gt;
&lt;Fields&gt;  

&lt;asp:TemplateField HeaderText="Notification Date"&gt;
&lt;HeaderTemplate&gt;&lt;span style="color:Red;"&gt;*&lt;/span&gt; Notification Date  &lt;/HeaderTemplate&gt;
&lt;InsertItemTemplate&gt;
&lt;asp:TextBox ID="txtNotificationDate" runat="server" Width="150" Text=""    /&gt;
&lt;cc1:CalendarExtender ID="CalendarExtender1" runat="server" TargetControlID="txtNotificationDate" PopupPosition="Right"/&gt;
&lt;/InsertItemTemplate&gt;
&lt;EditItemTemplate&gt;
&lt;asp:TextBox ID="txtNotificationDate" runat="server" Width="150" Text='&lt;%# Eval("NotificationDate", "{0:d}") %&gt;' /&gt;
&lt;cc1:CalendarExtender ID="CalendarExtender1" runat="server" TargetControlID="txtNotificationDate" PopupPosition="Right"/&gt;
&lt;/EditItemTemplate&gt;
&lt;/asp:TemplateField&gt;

&lt;asp:TemplateField HeaderText="Effective Date"&gt;       
&lt;InsertItemTemplate&gt;
&lt;asp:TextBox ID="txtEffectiveDate" runat="server" Width="150" Text=""    /&gt;
&lt;cc1:CalendarExtender ID="CalendarExtender2" runat="server" TargetControlID="txtEffectiveDate" PopupPosition="Right"/&gt;
&lt;/InsertItemTemplate&gt;
&lt;EditItemTemplate&gt;
&lt;asp:TextBox ID="txtEffectiveDate" runat="server" Width="150" Text='&lt;%# Eval("EffectiveDate", "{0:d}") %&gt;' /&gt;
&lt;cc1:CalendarExtender ID="CalendarExtender2" runat="server" TargetControlID="txtEffectiveDate" PopupPosition="Right"/&gt;
&lt;/EditItemTemplate&gt;
&lt;/asp:TemplateField&gt;

&lt;/Fields&gt;
&lt;/asp:DetailsView&gt;
</code></pre>
