Insert Record into SQL2005 from c Sharp DataGridView

[yousafc#]

AoA
I am Inserting Data From DataGridview to Sql2005.It Insert Perfectely.
The Problem is that when i insert record it alway insert 0 row with my other rows
The Code is below

            try
            {

                string con = "Data Source = FLOWER-PC;Database = MYFIRSTDATABASE;Integrated Security = True";
                SqlConnection cn = new SqlConnection(con);
                cn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = cn;                
                for (int i =0; i < dataGridView1.Rows.Count; i++)
                {
                    cmd.CommandText = "INSERT INTO PERSONALINFORMATION(pid,firstname) values('"
                                        + dataGridView1.Rows[i].Cells["pid"].Value + "','"
                                        + dataGridView1.Rows[i].Cells["firstname"].Value + "')";    
                        cmd.ExecuteNonQuery();

                }
                cn.Close();
                MessageBox.Show("Record Inserted Successfully");      
            }
            catch (Exception ex) { MessageBox.Show(ex.Message); }

Please Help and send me its Solution as soon as possible