Strip Non-Numeric characters from string function

<%
Function StripNonNumeric(strInput)
Dim iPos, sNew, iTemp
strInput = Trim(strInput)
If strInput <> "" Then
iPos = 1
iTemp = Len(strInput)
While iTemp >= iPos
If IsNumeric(Mid(strInput,iPos,1)) = True Then
sNew = sNew & Mid(strInput,iPos,1)
End If
iPos = iPos + 1
Wend
Else
sNew = ""
End If
StripNonNumeric = sNew
End Function
%>

Function stripNonNumeric(stringIn)
if stringIn <> "" then
dim stringOut
strIn = replace(stringIn,"'","")
For I = 1 to len(stringIn)
if isNumeric(mid(stringIn,I,1)) = true then stringOut = stringOut & mid(stringIn,I,1)
Next
stripNonNumeric = stringOut
else
stripNonNumeric = stringIn
end if
End Function