Excel 2007 : sort smallest number to largest

hello peeps

I have a code on one of my sheets which automatically sorts all the cells after user input. can someone tell me how to modd it so it sorts the number from smallest to largest? at the mo I have number such as 10, 15 20, 215, 60, etc etc it is ordering 215 before 60 because of the first digit.

here is the code

Private Sub Worksheet_Change(ByVal Target As Range)
    Columns(Target.Column).Sort _
        Key1:=Cells(1, Target.Column), _
        Order1:=xlAscending, _
        Header:=xlNo, _
        OrderCustom:=1, _
        MatchCase:=False, _
        Orientation:=xlTopToBottom
End Sub

Any help would be most appreciated.

Raj