I Want To Make Textbox Visible To True In Gridview When I Click On Edit Button Can Any One Help Me Out !

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "Update")
        {

            int RowIndex = Convert.ToInt32(e.CommandArgument);
          
            GridViewRow row = (GridViewRow)GridViewDept.Rows[RowIndex];
            
            Label deptno = (Label)row.FindControl("lblDeptNO" );
            TextBox deptname = (TextBox)row.FindControl("txtDeptName");
           
            TextBox deptloc = (TextBox)row.FindControl("txtloc");
            cn.Open();
            string query = "update dept set dname'" + deptname.Text + "','" + deptloc.Text + "' where deptno='" + deptno.Text + "'";
            cm = new SqlCommand(query, cn);
            cm.ExecuteNonQuery();
            cn.Close();
            ShowRecords();
        }
protected void GridViewDept_RowEditing(object sender, GridViewEditEventArgs e)
   {

       GridViewDept.EditIndex = e.NewEditIndex;
       GridViewDept.FindControl("txtDeptNO").Visible = true;
  GridViewDept.FindControl("txtDeptName").Visible = true;
  GridViewDept.FindControl("txtloc").Visible = true;

       ShowRecords();
   }