Accessing form components from thread

I think I have been unable to eleborate the problem. I want to load a combo box from a data base. Now, when I make a connection to the data base and retrieve the data, it takes time. and in that time the form remains statix and gives a look of hanged application. I want to overcome this. I want the form to display some sort of progress but its not working that way. I am unable to use thread since it does not allow to access form components and load them with value or alter their properties.