Editable Gridview with code behind data source from ODBC - asp.net

Question

I am trying to make a small gridview that lists the results of a query against a non standard SQL db, and with this information I want the user to be able to edit a column or two to update the data in the db. I know this is easy with an sqldatasource control but I lack that luxury and I am having trouble switching from my itemTemplates in the gridview to the edittemplates when I fire the gridview's edit event.
any pointers?
some code:
<asp:GridView ID="ExamEditGridView" runat="server" OnRowEditing="EditExam" OnRowUpdating="SaveEdit"
DataKeyNames="iproc_code" AllowSorting="true" AutoGenerateColumns="false" AutoGenerateEditButton="true">
<HeaderStyle BackColor="#006633" Font-Bold="True" ForeColor="White" />
<EditRowStyle BackColor="#999999" />
<Columns>
<asp:TemplateField HeaderText="Exam Title">
<ItemTemplate>
<asp:Label ID="col1" runat="server" Text='<%# Bind("rpt_descrip") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="EditText" runat="server" Text='<%# Bind("rpt_descrip") %>' Visible="false" />
</EditItemTemplate>
</asp:TemplateField>
<asp:BoundField HeaderText="Short Description" DataField="short_descrip" />
<asp:BoundField HeaderText="Description" DataField="descrip" />
<asp:BoundField HeaderText="Sched Note" DataField="sched_note" />
</Columns>
</asp:GridView>
code behind:
(the query is just a simlpe select statement)
string mod_id = modSelect.SelectedValue;
string query = qry + mod_id;
using (OdbcConnection connection = new OdbcConnection(DbConnectionString))
{
OdbcDataAdapter adapter = new OdbcDataAdapter(query, connection);
DataTable dt = new DataTable();
connection.Open();
adapter.Fill(dt);
ExamEditGridView.DataSource = dt;
ExamEditGridView.DataBind();
}
the gridview is databound when a dropdown lists index changes, which gives me the mod_id for the query

Answer 1

I ended up getting it working, I didn't realize I had to set the gridview's editindex value and redatabind to toggle edit mode
code:
protected void EditExam(object sender, GridViewEditEventArgs e)
{
ExamEditGridView.EditIndex = e.NewEditIndex;
ExamEditGridView.DataSource = Session["data"];
ExamEditGridView.DataBind();
}
protected void CancelEdit(object sender, GridViewCancelEditEventArgs e)
{
ExamEditGridView.EditIndex = -1;
ExamEditGridView.DataSource = Session["data"];
ExamEditGridView.DataBind();
}