Compile error: type mismatch

[Bluen]

Actually this is from text book.
My code is:

Private Sub mnuCheck_Click()
Dim TempDate As Date
CheckFile = Dir(ThisDir, vbNormal)

Do While CheckFile <> ""

    If Right(CheckFile, 3) = "cqu" Then
    Open CurDir + "\Car Quotes\" + CheckFile For Input As #1
    Line Input #1, TempDate

    If Date - TempDate > 30 Then
    txtDate = TempDate
    End If
    End If
CheckFile = Dir
Loop
End Sub

when I tested running it, error code appear and the 'TempDate' is highlighted yellow.
could someone please tell where my mistake is..?

p/s:Just tell me if I need to add more information if the code above is not enough