Get Values From Dropdown Button of a StringEdit Control

Hi,

I'm new in AX 2009 using the developer section (AOT). I have successfully coded the list values I want to see in the dropdown list of the StringEdit control. I am having a problem on how can I get the specific selected value in the dropdown. I am planning to used to store in a variable or use it the WHERE statement of an SQL query. Please help!!!

Thanks,

Jeremy