private void LoadChuHo()
{
cboMaChuHo.Items.Clear();
cboTenChuHo.Items.Clear();
var danhSachChuHo = context.layDanhSachNguoiDan();
foreach (var chuHo in danhSachChuHo)
{
cboMaChuHo.Items.Add(chuHo.ma.ToString().Trim());
cboTenChuHo.Items.Add(chuHo.ten.ToString().Trim());
}
}