How to validate controls in each column of a gridview - asp.net

Question

I would like to validate columns in an asp:Gridview but am unsure how to do so as all the tutorials I have found show a previous version on Microsoft Visual Studio (I am using 2010).
How do I validate each column of the Gridview?
Thanks
This is the code of my Gridview generated by visual studio.
<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False"
DataKeyNames="registrationNo" DataSourceID="SqlDataSource3"
onselectedindexchanged="GridView2_SelectedIndexChanged">
<Columns>
<asp:BoundField DataField="fullName" HeaderText="fullName"
SortExpression="fullName" />
<asp:BoundField DataField="address" HeaderText="address"
SortExpression="address" />
<asp:BoundField DataField="work" HeaderText="work"
SortExpression="work" />
<asp:BoundField DataField="home" HeaderText="home" SortExpression="home" />
<asp:BoundField DataField="mobile" HeaderText="mobile"
SortExpression="mobile" />
<asp:BoundField DataField="registrationNo" HeaderText="registrationNo"
InsertVisible="False" ReadOnly="True" SortExpression="registrationNo" />
<asp:ButtonField ButtonType="Button" CommandName="Edit" HeaderText="Edit"
ShowHeader="True" Text="Edit" />
<asp:ButtonField ButtonType="Button" CommandName="Update" HeaderText="Update"
ShowHeader="True" Text="Update" />
<asp:ButtonField ButtonType="Button" CommandName="Delete" HeaderText="Delete"
ShowHeader="True" Text="Delete" />
</Columns>
<HeaderStyle BorderColor="#33CC33" />
<RowStyle BorderStyle="Double" Font-Names="Monotype Corsiva" />
</asp:GridView>

Answer 1

//native asp.net clientside validation (ATLAS Ajax)
Instead of using BoundFields you should use TemplateField. This will allow you to add Validation controls in the field i.e.
Tutorial from 2007 which is still pertinent to this question
//serverside validation
In order to validate the values on the server side you have a couple of options:
a) add a CustomValidator pointing to codebehind server validation method i.e. msdn doc
b) on the gridviews RowUpdating method you could validate manually (this would also be for batch updates)