Vb.net for 4 textbox 1 datagridview 1 button how to inert values in sql database

i am trying sales module in vb.net for 4 textbox 1 datagridview 1 button how to inert values in sql database but not success how to solve the problam


con.Open()
com.CommandText = "insert into three(sid,supid,supname,supperson) values((@sid,@supid,@supname,@supperson)"
com.Parameters.AddWithValue("@sid", TextBox1.Text)
com.Parameters.AddWithValue("@supid", TextBox2.Text)
com.Parameters.AddWithValue("@supname", TextBox3.Text)
com.Parameters.AddWithValue("@supperson", TextBox4.Text)
For i As Integer = 0 To DataGridView1.Rows.Count - 1
com.CommandText = "insert into three(pno,pname,qty,price) values((@pno,@pname,@qty,@price)"
com.Parameters.AddWithValue("@pno", DataGridView1.Rows(i).Cells(0).Value)
com.Parameters.AddWithValue("@pname", DataGridView1.Rows(i).Cells(1).Value)
com.Parameters.AddWithValue("@qty", DataGridView1.Rows(i).Cells(2).Value)
com.Parameters.AddWithValue("@price", DataGridView1.Rows(i).Cells(3).Value)
com.ExecuteNonQuery()
Next
connection.Close()