Thanks! It works, but another question...
It works, both! For now, I’m using Erel´s method.
Now I added another ComboBox (Tax) that it contains ítems ( A, B, C) whit another assigned cost (1,2,3).
Whit a button click, I calculate total cost of both items input previously.
Sub Button1_Click
Textbox3.Text=textbox1.Text+textbox2.Text
End Sub
It works perfectly, My question is: I can calculate and show automatically these result without the button?
Sub Globals
End Sub
Sub App_Start
Form1.Show
ArrayList1.Add(10)
ArrayList1.Add(20)
ArrayList1.Add(30)
ArrayList2.Add(1)
ArrayList2.Add(2)
ArrayList2.Add(3)
End Sub
Sub ComboBox18_SelectionChanged (Index, Value)
TextBox1.Text = ArrayList1.Item(Index)
End Sub
Sub ComboBox2_SelectionChanged (Index, Value)
TextBox2.Text = ArrayList2.Item(Index)
End Sub
Sub Button1_Click
Textbox3.Text=textbox1.Text+textbox2.Text
End Sub
Thanks for his responses.