VB.Net The variable name '@srno' has already been declared. variable names must be unique within a query batch or stored procedure.

Bellow is the Button Click code which i was trying. Getting error:

The variable name '@srno' has already been declared. variable names must be unique within a query batch or stored procedure.

 Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
        If con.State = ConnectionState.Open Then
            con.Close()
        End If
        '''+++++++++++++++++++++++++++
        Dim i As Integer
        Dim rs1 As String
        '''++++++++++++++++++++++++++++++++
   
        '================================================================================================================================

        Try
            For i = 0 To DataGridView1.Rows.Count - 1

                rs1 = "INSERT INTO tblProductsve(srno,ItemCode, ProDes, Price,Qty,amt,subtot) VALUES(@srno,@ItemCode, @ProDes, @Price,@Qty,@amt,@subtot)"

                Dim cmd As New SqlClient.SqlCommand(rs1, con)
                
                cmd.Parameters.AddWithValue("srno", DataGridView1.Rows(i).Cells(0).Value)
                cmd.Parameters.AddWithValue("ItemCode", DataGridView1.Rows(i).Cells(1).Value)
                cmd.Parameters.AddWithValue("ProDes", DataGridView1.Rows(i).Cells(2).Value)
                cmd.Parameters.AddWithValue("Price", DataGridView1.Rows(i).Cells(3).Value)
                cmd.Parameters.AddWithValue("Qty", DataGridView1.Rows(i).Cells(4).Value)
                cmd.Parameters.AddWithValue("amt", DataGridView1.Rows(i).Cells(5).Value)
                cmd.Parameters.AddWithValue("subtot", TextBox1.Text)

                con.Open()

                cmd.ExecuteNonQuery()

                con.Close()

            Next

            MessageBox.Show("Save Successully ")

        Catch ex As Exception
            MsgBox(ex.Message)

        End Try
        

    End Sub