I want to generate multiple checkbox lists for each item selected in listbox.
The requirement is i have a listbox which shows some categories in a list.
When i click on each category, it should show a list of services in another checkbox list on the right side. The problem i am facing is due to postback, i am not able to retain the values of the selected items in the chcklist.

If i select category1 and choose 5 services from checkbox list and go to second category and select another 2 services, what ever i have selected earlier is not retained. Please suggest an alternative solution to this.