Count instances of one string in another

<%
    ' Copyright (c) 2008, reusablecode.blogspot.com; some rights reserved.
    '
    ' This work is licensed under the Creative Commons Attribution License. To view
    ' a copy of this license, visit http://creativecommons.org/licenses/by/3.0/ or
    ' send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California
    ' 94305, USA.
 
    ' Count the number of occurences of one string in another.
    function InstrCount(haystack, needle)
        if needle <> "" then
            InstrCount = UBound(Split(haystack, needle))
        end if
    end function
%>