Visual Basic 6 (VB6)

I have Created a page in vb 6.0 .In that form i have used a combo box in which two fields are inserted as Liter and Percentage and fields of that's respective items are given in that form.So i want that if i select liter then percent's fields should be disappeared and only liter fields should be shown and if i select percent fields then liter fields should be shown .
So for that please suggest me code and property which i have to done so that i can complete my project...............It's Urgent