when I try to insert values I got this error:
I Used this code

myConnection = New SqlConnection(connectionstring)
        myConnection.Open()

        Try

            Dim insert1 As SqlCommand = New SqlCommand("INSERT INTO [VBP].[dbo].[Return_Total] ([RGN0],[Date] ,[Totalamount],[User_Id],[C_NIC],[Comments],[Bill_No]) values ('" & Val(TextBox2.Text) & "','" & DateTimePicker1.Value.Date & "','" & TextBox4.Text & "','" & TextBox6.Text & "','" & TextBox3.Text & "','" & TextBox5.Text & "','" & Val(TextBox8.Text) & "'", myConnection)
            insert1.ExecuteNonQuery()
            insert1.Cancel()
            MessageBox.Show("New Data has Added")

        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Critical, "ERROR")
        Finally
        End Try
        myConnection.Close()

the no is the no I'm giving.............

Just on the surface, it looks like you're missing a ")", this might work,

Dim insert1 As SqlCommand = New SqlCommand("INSERT INTO [VBP].[dbo].[Return_Total] ([RGN0],[Date] ,[Totalamount],[User_Id],[C_NIC],[Comments],[Bill_No]) values ('" & Val(TextBox2.Text) & "','" & DateTimePicker1.Value.Date & "','" & TextBox4.Text & "','" & TextBox6.Text & "','" & TextBox3.Text & "','" & TextBox5.Text & "','" & Val(TextBox8.Text) & "'"), myConnection)

Thank you.....................