Referencing a field in a subform (MS Access)

So I have added mandatoryWorkTime as a String variable and called it in a messagebox, I think I am going about referencing the cell all wrong though, can you tell me what this should look like? All of the names listed below.

Form = CompleteTaskForm
Subform = CompleteTaskSubform
Control? = Tasks subform
Table = Tasks
Field = Completed By 1 (Short text data type)

This is what the VBA currently looks like...


Thanks

IN order to troubleshoot, make the form Field of "Completed By 1" into "CompletedByOne", or "Completed_By_1".

The messagebox will display what ever you have loaded into that new variable.

Thanks for the suggestions...I managed to muddle through and figured out the error in my referencing with help from some guidance notes posted online by Allen Browne http://allenbrowne.com/casu-04.html This grew quite a bit due to unexpected behavior but have added my code below for reference...Perhaps you know a better way?

Private Sub CompleteTaskButton_Click()
On Error GoTo HandleError

If IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Completion Date]) = True Then
MsgBox ("Please enter a completion date.")
Else
If IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Time Worked (hours)]) = True Then
MsgBox ("Please enter number of hours worked.")
Else
If IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Number of Employees Worked]) = True Then
MsgBox ("Please enter number of employees worked.")
Else
If IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Completed By 1]) = True Then
MsgBox ("Please enter name or initials of all employees that worked on PM.")
Else
'Save the record
DoCmd.RunCommand acCmdSaveRecord

'Close the form
DoCmd.Close ObjectType:=acForm, ObjectName:=Me.Name, Save:=acSavePrompt
End If
End If
End If
End If

HandleExit:
Exit Sub

HandleError:
MsgBox Err.Description
Resume HandleExit
End Sub
_____________________________________________________________________________________________________________
Private Sub Form_Unload(Cancel As Integer)
If IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Completion Date]) = True And IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Time Worked (hours)]) = True And IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Number of Employees Worked]) = True And IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Completed By 1]) = True Then
userresponse = MsgBox("Are you sure you want close?", vbYesNo, "Database Information")
Select Case userresponse
Case 6
Cancel = False
Case 7
Cancel = True
'this line keeps my own form open in my own case
DoCmd.OpenForm "CompleteTaskForm"
End Select
Else
If IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Completion Date]) = True Or IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Time Worked (hours)]) = True Or IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Number of Employees Worked]) = True Or IsNull(Forms.CompleteTaskForm.CompleteTaskQuerySubform.Form.[Completed By 1]) = True Then
MsgBox ("Please either complete Completion Date, Hours Worked, Employees Worked and Completed By, or clear any partial info added to these before closing.")
Cancel = True
DoCmd.OpenForm "CompleteTaskForm"
Else
'Save the record
DoCmd.RunCommand acCmdSaveRecord

Cancel = False
End If
End If
End Sub