Using web user controls as variables/objects in classes.

I have created four web user controls:

OpenQuestion.ascx,
YesNoQuestion.ascx,
MultipleChoiceQuestionSingleAnswer.ascx, and
MultipleChoiceQuestionMultipleAnswer.ascx,

which reside in a directory called 'Controls'.

When I try to do the following:

 1 public partial class ApplyForJob : System.Web.UI.Page
2 {
3 private OpenQuestion openQuestion;
4 private YesNoQuestion yesNoQuestion;
5 private MultipleChoiceQuestionSingleAnswer mcQuestionSingle;
6 private MultipleChoiceQuestionMultipleAnswer mcQuestionMultiple;
7 ...
 
The class does not recognise the user controlsi.e. OpenQuestion ...