Cascading dropdowns in the event registration form.

[pmimumbai]

I want to add custom questions to a registration form. The simple logic I want to implement is - 
1. Are you a member? - Yes/No.

2. If answer is Yes then show dropdown to select a region? - There are seven regions in dropdown.
3. There are 7 dropdowns, one each for the region. Each dropdown has location list for the associated region. 
4. When user selects "region 1" then I want to show only the location dropdown associated/linked to the region1 and so on. 
5. If answer to 1 is No then skip to last question.
I added the dropdowns and added region <-> location relationship using the "add skip logic". But it does not work as intended. Whatever option I select in the Region dropdown, all dropdowns for locations are displayed. For answer "No", the last question is displayed as intended.
How can I resolve this issue?