Can You Fill A Text Box Using A Query

Hi, newbie needs help!

I am trying to make a courses registration database. I have 3 tables; tblContacts [ContactID], [FitstName], [LastName] [Etc..] [Etc..]
tblCourseRegistration [RegID], [ContactID] [CourseID] and tblCourses [CourseID], [RegID], [CourseName], [StartDate], [AvailablePlaces]
I have created a form called Test1 that displays The CourseID, CourseName, StartDate EndDate and an unbound textbox called PlacesLeft. I would like to display in this text box the number of places that are still available on a particular course. I've written a querie that counts the CourseID's in the course registration table this works ok but I want it to place the value in the PlacesLeft text box. Then I can do a simple calculation based on the PlacesAvailable textbox. Anyone any idea how to do this My querie reads
SELECT Count([CourseID])
FROM tblCourseRegistration
WHERE (((tblCourseRegistration.CourseID)=(Forms.Test1.Co urseID)));

I tried another method which includes a command button that when clicked tries to run the following
Dim MyRS As ADODB.Recordset, strSQL As String

Set MyRS = New ADODB.Recordset
strSQL = "SELECT Count([CourseID])FROM tblCourseRegistration WHERE (((tblCourseRegistration.CourseID) = (Forms.Test1.IDNo)))"
MyRS.Open strSQL, CurrentProject.Connection, adOpenKeyset, adLockOptimistic

If MyRS.NoMatch Then
Me.PlacesLeft = ""
Else
Me.PlacesLeft = MyRS.Fields(0)
but Access (Ver 2000) does not like the noMatch and shows it as an error.
I would be very grateful if someone could show me how to sort this out!

Many thanks in advance