Unable to update in gridview

[Terence]

Hi,

I have a web user control which includes a gridview and a sqldatasource. It
also has a property called TableName which is used to populate the gridview.
However, i'm running into a problem where i can select and delete row but i
cannot update a row.

Here is the code in the usercontrol

protected void Page_Load(object sender, EventArgs e)
{

if (!Page.IsPostBack)
{
if (Roles.IsUserInRole("Management"))
{
GridView1.AutoGenerateEditButton = true;
GridView1.AutoGenerateDeleteButton = true;
}
}
SqlDataSource1.ConnectionString = Session["ConnStr"].ToString();
//SqlDataSource1.SelectCommand = "SELECT [Studio], [code], [Name]
FROM [Studio]";
//SqlDataSource1.UpdateCommand = "Update Studio set [code] = @Code,
[Name] = @Name where [Studio] = @Studio";
//SqlDataSource1.DeleteCommand = "Delete from Studio where [Studio]
= @Studio";
SqlDataSource1.DeleteCommand = "Delete from " + tablename + " where
[" + tablename + "] = @" + tablename;
SqlDataSource1.SelectCommand = "SELECT [" + tablename + "], [code],
[Name] FROM [" + tablename + "]";
SqlDataSource1.UpdateCommand = "Update [" + tablename + "] set
[code] = @Code, [Name] = @Name where [" + tablename + "] = @" + tablename;
SqlDataSource1.DataBind();

string[] arListType = new string[1];
arListType[0] = tablename;
GridView1.DataKeyNames = arListType;
BoundField bf = new BoundField();
bf.DataField = tablename;
bf.HeaderText = tablename;
//bf.Visible = false;
bf.ReadOnly = true;

BoundField bf2 = new BoundField();
bf2.DataField = "Code";
bf2.HeaderText = "Code";

BoundField bf3 = new BoundField();
bf3.DataField = "Name";
bf3.HeaderText = "Name";

GridView1.Columns.Clear();
GridView1.Columns.Add(bf);
GridView1.Columns.Add(bf2);
GridView1.Columns.Add(bf3);

GridView1.DataBind();

}

Does anyone has any idea why and how to fix it?

Thanks!