InfoPath Dev

 Hi. I am not an expert in C# and I would like some help with the events. What I am trying to do is: I have a dropdownlist with values. When I select a value I want another dropdownlist to be enabled. When I click on the second dropdownlist I want it to be populated, using an sql query with some values using as variable the value from the first dropdownlist. I know how to do the code, I do not know which event I have to use. In the second case could be CLICKED. In the first case, I do not know. Thank you!

for the first case just use conditional formatting on the second dropdown

if dropdown1 is blank

disable this conrol

 Hi. Thank you for your answer. There is one more thing. If I want to enable a dropdownlist when I press on a option button how do i do this? Thank you!

 I am asking because the default value of option button is null. I cannot specify null in conditional formating.

 I got it sorry. I had several option buttons. It works fine. Thank you.