Forms :: Make One Combo List Depend On Another

I have a combo: cmb_TrainingType. The sql is:

Code:
SELECT tblTrainingType.TypeID, tblTrainingType.Type FROM tblTrainingType ORDER BY tblTrainingType.Type;

My second combo (the one that should be filtered based on the Type chosen above) is cmb_Project_Title. The sql I have written (which isn't working) is:

Code:
SELECT tblCourseDetails.CDID, tblCourseDetails.Project_Title FROM tblCourseDetails WHERE (((tblCourseDetails.TypeID)=Forms!frmResourcing.cmb_Training_Type) And ((tblCourseDetails.Type)=Forms!frmResourcing.cmb_Training_Type)) ORDER BY tblCourseDetails.[Project_Title];

Both of the tables that are referenced have the fields TypeID and Type.