Function question

Private Function GetFeedDisappearance(x As Integer, Y As Integer) As Integer

GetFeedDisappearance = x / Y
'Takes x (total feed used) and devides it by X(total days)

End Function

Private Function isDateBetween(tmpDate As String, DateStart As String, DateEnd As String, Optional Exclusive As Boolean = True) As Boolean
If (txtstart = "mm/dd/yy") Or (txtend = "mm/dd/yy") Then
MsgBox "Erorr, Invalid date Format"
Else
    Dim tmpVal As Integer
    If Exclusive Then tmpVal = 1
    If Not Exclusive Then tmpVal = 0
    isDateBetween = True
    Debug.Print "DateStart - tmpDate = " & DateDiff("d", DateStart, tmpDate)
    If DateDiff("d", DateStart, tmpDate) < tmpVal Then
           isDateBetween = False
    ElseIf DateDiff("d", tmpDate, DateEnd) < tmpVal Then
           isDateBetween = False
    End If
End If
End Function


Private Sub cmdCheck_Click()
total = 0
If (cmbID = "") Or (txtstart = "mm/dd/yy") Or (txtend = "mm/dd/yy") Then
MsgBox "Error, Invalid input."
Else


If (cmbID = txtID) And (txtDropID = 1) Then
        Dim x As String
        x = Trim(cmbID.List(cmbID.ListIndex))
        cnMain.Recordset.Filter = "DropID= '" & x & " '"
        
        
        If isDateBetween(txttemp, txtstart, txtend) And (txtfull = 1) Then
        total = total + txtTotalByWeight
        Else
            With cnMain.Recordset
    .MoveNext
    End With
        End If
    End If


End If

txtAverage = total
End Sub