How Do I Compare/Check Validation From A Gridview(Row) With A Textbox

so can u help me with this ?

<asp:CompareValidator ID="CompareValidator1" runat="server"
ControlToValidate="TextBox1" ErrorMessage="Maximum value 100000"
Operator="LessThanEqual" Type="Integer" ValueToCompare="100000">




CompareValidator1.ValueToCompare = Label1.Text;
CompareValidator1.ErrorMessage = string.Format("Maximum value is {0}", Label1.Text);


but this is fixed size.. and i tried with label and text
i need it to compare from gridview value. which i will check through textbox