How to disable editing in specific column inside gridview

https://www.dropbox.com/s/nwjfhwxh35w088k/grid.png</a>
i want to disable editing on the column Item_IP

my gridview code
<pre lang="HTML">
<pre lang="xml"><asp:GridView ID="GridView1" runat="server"
                            CellPadding="4" ForeColor="#333333" GridLines="Vertical" Height="265px"
                            Width="100%" HorizontalAlign="Left" onrowediting="gridView_RowEditing"
            onrowcancelingedit="gridView_RowCancelingEdit"
            onrowupdating="gridView_RowUpdating" onrowdeleting="gridView_Rowdeleting">
                            <AlternatingRowStyle BackColor="White" />
                            <Columns>
     <asp:TemplateField>

      <ItemTemplate>
      <asp:Button ID="btnedit" CommandName="EDIT" runat="server" Text="EDIT" />
      </ItemTemplate>
      <EditItemTemplate>
      <asp:Button ID="btnupdate" CommandName="Update" runat="server" Text="Update" />
      <asp:Button ID="btnCancel" CommandName="Cancel" runat="server" Text="Cancel" />
      <asp:Button ID="btnDelete" CommandName="Delete" runat="server" Text="Delete" />

      </EditItemTemplate>

     </asp:TemplateField>
    </Columns>
                            <EditRowStyle BackColor="#2461BF" BorderWidth="1px" />
                            <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                            <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" Height="3px" />
                            <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
                            <RowStyle BackColor="#EFF3FB" />
                            <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
                            <SortedAscendingCellStyle BackColor="#F5F7FB" />
                            <SortedAscendingHeaderStyle BackColor="#6D95E1" />
                            <SortedDescendingCellStyle BackColor="#E9EBEF" />
                            <SortedDescendingHeaderStyle BackColor="#4870BE" />
                        </asp:GridView>
</pre>


and the C# code
&lt;pre lang=&quot;c#&quot;&gt;

    public partial class _default : System.Web.UI.Page
    {

        DataTable dt;
        protected void Page_Load(object sender, EventArgs e)
        {

            if (!IsPostBack)
            {
                dt = new DataTable();
                MakeTable();
            }
            else
            {
                dt = (DataTable)ViewState[&quot;dt&quot;];
            }
            ViewState[&quot;dt&quot;] = dt;

        }
        protected void MakeTable()
        {
            dt.Columns.Add(&quot;Item_IP&quot;);
            dt.Columns.Add(&quot;Name&quot;);
            dt.Columns.Add(&quot;Price&quot;);
        }




        protected void subCatClick(object sender, EventArgs e)
        {
            Button btn = (Button)sender;
            int item_ip = btn.TabIndex;
            try
            {
                OleDbConnection myOleDbConnection = new OleDbConnection(connectionString);
                myOleDbConnection.Open();
                OleDbCommand myOleDbCommand = myOleDbConnection.CreateCommand();
                myOleDbCommand.CommandText = &quot;select arabic_name,sale_price from item where ip=&quot; +item_ip;
                OleDbDataReader dr = myOleDbCommand.ExecuteReader();
                dr.Read();
                DataRow drow = dt.NewRow();
                drow[&quot;Item_IP&quot;] = item_ip.ToString();
                drow[&quot;Name&quot;] = dr[&quot;ARABIC_NAME&quot;].ToString();

                drow[&quot;Price&quot;] = dr[&quot;SALE_PRICE&quot;].ToString();

                dt.Rows.Add(drow);
                GridView1.DataSource = dt;
                GridView1.DataBind();

                dr.Close();
                myOleDbConnection.Close();

            }
            catch (Exception eee)
            {
                Response.Write(&quot;&amp;lt;script&gt;alert(&#39;error in subCatClick&#39;)&amp;lt;/script&gt;&quot;);
            }


        }
        protected void gridView_RowEditing(object sender, GridViewEditEventArgs e)
        {
            GridView1.EditIndex = e.NewEditIndex;
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }
        protected void gridView_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
        {
            GridView1.EditIndex = -1;
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }
        protected void gridView_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {
            GridViewRow row = (GridViewRow)GridView1.Rows[e.RowIndex];


            string ip    = ((TextBox)row.Cells[1].Controls[0]).Text;


                string name = ((TextBox)row.Cells[2].Controls[0]).Text;

                string price = ((TextBox)row.Cells[3].Controls[0]).Text;



                DataRow[] datarow = dt.Select(&quot;Item_IP=&#39;&quot; + ip + &quot;&#39;&quot;);
                dt.Rows[e.RowIndex].BeginEdit();
                dt.Rows[e.RowIndex][&quot;Name&quot;] = name;

                dt.Rows[e.RowIndex][&quot;Price&quot;] = price;

                dt.Rows[e.RowIndex].EndEdit();
                dt.AcceptChanges();
                GridView1.EditIndex = -1;
                GridView1.DataSource = dt;
                GridView1.DataBind();


        }
        protected void gridView_Rowdeleting(object sender, GridViewDeleteEventArgs e)
        {
            GridViewRow row = (GridViewRow)GridView1.Rows[e.RowIndex];
            string ip = ((TextBox)row.Cells[1].Controls[0]).Text;
            string name = ((TextBox)row.Cells[2].Controls[0]).Text;
            DataRow[] datarow;
            datarow = dt.Select();
            datarow = dt.Select(&quot;Item_IP=&#39;&quot; + ip + &quot;&#39; AND Name=&#39;&quot;+ name +&quot;&#39;&quot;);
            foreach (DataRow r in datarow)
            { r.Delete(); break; }
            GridView1.EditIndex = -1;
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }

    }
}

&lt;/pre&gt;</pre>