Vista - VBA run-time error

What is wrong with this code?!! I am getting a run-time error (-2147217904
80040e10) error "No value given for one or more required parameters.
If I substitute the DeptID "5" in the query it works just fine. Is there
something wrong with my rs.Open statement?
I made the variable SelectDept = Combo33

Dim rs As ADODB.Recordset
Set rs = New ADODB.Recordset
rs.ActiveConnection = CurrentProject.Connection
rs.CursorType = adOpenStatic

'Position pointer to DeptID(recordset) selected in Combo33

rs.Open "SELECT tblDSRDMTasks.DeptID, tblDSRDMTasks.DSRPartNo,
tblDSRDMTasks.TaskCode, ztblDDT.DSRTask1, ztblDDT.DSRTask2, ztblDDT.DSRTask3,
ztblDDT.DSRTask4, ztblDDT.DSRTask5 FROM tblDSRDMTasks LEFT JOIN ztblDDT ON
(tblDSRDMTasks.DeptID=ztblDDT.DeptID) AND (tblDSRDMTasks.DSRPartNo =
ztblDDT.DSRPartNo) WHERE (((tblDSRDMTasks.DeptID) = [SelectDept]))"