Does Any Suggestion how to do ?

Question

For my Project is are Order System , need 3-time select

1.Type(Food/Drink/..) 2.What Food?What Drink? 3 What Branding ?

[The structure like This]

 

Now i use `if ComboxX.SelectItem.ToString().Equal(""))` to do , but when i do combobox3, i very confuse i need write `if ComboxX.SelectItem.ToString().Equal("X"))` n Time ?

Do Any Good ides to Coding for this ?