protected void btnUpdate_Click(object sender, EventArgs e)
 {
     bc = new Bol_City();
     ct = new City();
     if (txtID.Text == "")
     {
         Response.Write("Vui long nhap ten hay id can cap nhat !!!");
         txtID.Focus();
     }
     else
     {
         if (DropDownList4.SelectedValue.ToString() == "ByID")
         {
             if (bc.CheckCityExistByID(Convert.ToInt32(txtSearch.Text)) == 1)
             {
                 if (TextBox1.Text == "")
                 {
                     Response.Write("Ban dang de trong phan cap nhat !!!");
                     TextBox1.Focus();
                 }
                 else
                 {
                     ct.Ci_ID             = Convert.ToInt32(TextBox1.Text);
                     GridView1.DataSource = bc.UpdateCityByID(ct);
                     GridView1.DataBind();
                     Response.Write("Update thanh cong");
                 }
             }
             else
             {
                 Response.Write("ID nay khong ton tai !!!");
             }
         }
         else if (DropDownList4.SelectedValue.ToString() == "ByName")
         {
             if (bc.CheckCityExistByName(txtSearch.Text) == 1)
             {
                 ct.Name = TextBox1.Text;
                 GridView1.DataSource = bc.UpdateCityByName(ct);
                 GridView1.DataBind();
             }
             else
             {
                 Response.Write("Name nay khong ton tai !!!");
             }
         }
     }
 }
 protected void btnSearch_Click(object sender, EventArgs e)
 {
     bc = new Bol_City();
     ct = new City();
     if (txtSearch.Text == "")
     {
         Response.Write("Vui long nhap tu khoa muon tim !!!");
         txtSearch.Focus();
     }
     else
     {
         if (DropDownList1.SelectedValue.ToString() == "ByID")
         {
             if (bc.CheckCityExistByID(Convert.ToInt32(txtSearch.Text)) == 1)
             {
                 ct.Ci_ID             = Convert.ToInt32(txtSearch.Text);
                 GridView1.DataSource = bc.SelectCityByID(ct);
                 GridView1.DataBind();
             }
             else
             {
                 Response.Write("ID nay khong ton tai !!!");
                 txtSearch.Focus();
             }
         }
         else if (DropDownList1.SelectedValue.ToString() == "ByName")
         {
             if (bc.CheckCityExistByName(txtSearch.Text) == 1)
             {
                 ct.Name = txtSearch.Text;
                 GridView1.DataSource = bc.SelectCityByName(ct);
                 GridView1.DataBind();
             }
             else
             {
                 Response.Write("Name nay khong ton tai !!!");
                 txtName.Focus();
             }
         }
     }
 }
 protected void btnDelete_Click(object sender, EventArgs e)
 {
     bc = new Bol_City();
     ct = new City();
     if (txtDelete.Text == "")
     {
         Response.Write("Nhap id hay ten can xoa !!!");
         txtDelete.Focus();
     }
     else if (DropDownList4.SelectedValue.ToString() == "ByID")
     {
         if (bc.CheckCityExistByID(Convert.ToInt32(txtSearch.Text)) == 1)
         {
             ct.Ci_ID             = Convert.ToInt32(TextBox1.Text);
             GridView1.DataSource = bc.DeleteCityByID(ct);
             GridView1.DataBind();
         }
         else
         {
             Response.Write("ID nay khong ton tai !!!");
         }
     }
     else if (DropDownList4.SelectedValue.ToString() == "ByName")
     {
         if (bc.CheckCityExistByName(txtSearch.Text) == 1)
         {
             ct.Name = TextBox1.Text;
             GridView1.DataSource = bc.DeleteCityByName(ct);
             GridView1.DataBind();
             Response.Write("Xoa thanh cong !!!");
         }
         else
         {
             Response.Write("Name nay khong ton tai !!!");
         }
     }
 }