Need VB.net help please.....

Question

Hi guys Ive got a from with 4 textboxes on it, cost,selling,m/up,gp
when i enter cost and selling it works out the gp and m/up

Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Selling.TextChanged
        Try
            mup.Text = Format(Val((Selling.Text) - Val(Cost.Text)) / Val(Cost.Text) * 100, "0.00")
            gp.Text = Format(Val((Selling.Text) - Val(Cost.Text)) / Val(Selling.Text) * 100, "0.00")
        Catch ex As Exception

        End Try

    End Sub

this works but now i want the selling,gp and m/up to change when i change the gp and i cant seem to get that working
i've got the Fromula for that but i keep getting errors or it doesn't change

this is the second part

Private Sub TextBox4_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles gp.TextChanged
        Try
            'selling =              cost *            (1 + m/up%)
            Selling.Text = Val(Cost.Text) * (1 + Val(mup.Text) / 100)

        Catch ex As Exception

        End Try
    End Sub

any help would really be appreciated

thanks

PJ Martins · Answer

calculating the reverse formula to solve selling I get this: Selling.Text = 100 * Val(Cost.Text) / (100 - Val(gp.Text)); See if that gives you what you're looking for.

Ryan steenkamp · Answer

Hi Pj Yes it should but i just need to understand the logics first if i change gp it should change selling price. if i get that working i can do the same for gp and m/up when i run the application and enter a value into cost and selling it generates my m/p and gp and it works but now i need to reverse that when i change the gp it should change my selling acording to the formule in text4_changed but it doesn't work it does'nt change because i state that gp's text should be this gp.Text = Format(Val((Selling.Text) - Val(Cost.Text)) / Val(Selling.Text) * 100 0.00) now if try and type a different value in there it doesn't do anything because i toldit to be this gp.Text = Format(Val((Selling.Text) - Val(Cost.Text)) / Val(Selling.Text) * 100 0.00) so it keeps going back to the original value hope this is clear thanks foryour reply. :-)

PJ Martins · Answer

In your TextBox4_TextChanged you're handling the gp's text change however your formula does not incorporate gp's value shouldn't gp.Text be incorporated in your formula somewhere?