We need to implement 2 level menu, the problems we are facing in implementation are as below:
1. We have to disable 1st level menu click. How to disable it? Every item in 1st level has child items. (Currently on clicking on 1st level menu item it hides 1st level of menu items and the it's child items does not disappears)

2. We have long list of items so we have added scroll to 2nd level child items. But when we click on scroll bar to scroll up/down, the parent(1st level) menu disappears.. How to solve this issue?