Only selected type can view services

[eyucks]

Hello all,

I want to create new type with selected services only. For example, I create type's name "Internal" then i create Service's name "Computer","Router" and "Switch".
When we want to create ticket, we choose Type=Internal, then at service section , I want only Computer,Router and Switch can see in Service section, not others.

Could you help me? I'm appreciate if anyone could help.