private void dgvContracts_CellClick(object sender, DataGridViewCellEventArgs e)
{
string index = dgvContracts.CurrentRow.Cells[1].Value.ToString();
string index1 = dgvContracts.CurrentRow.Cells[3].Value.ToString();
bl.disPlayID(txtIDBuyer, dgvContracts);
bl.disPlayCusName(txtNameBuyer, index);
bl.disPlayEmpID(txtIDSeller, dgvContracts);
bl.disPlayEmpName(txtNameSeller, index1);
}