Vba Macro Error: Compile Error Named Argument Not Found

I have some code that, although works fine in Excel 2003, does not in Excel 1997. I receive this error when I try running it:

COMPILE ERROR:
NAMED ARGUMENT NOT FOUND

Sub HPVAL()
Dim r As Range, myStr As String
myStr = "HP"
Set r = Cells. Find(What:=myStr, After:=ActiveCell, LookIn:=xlFormulas, LookAt _
:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, MatchCase:= _
False, SearchFormat:=False)
If Not r Is Nothing Then
r = r.Value
While Not r Is Nothing
Set r = Cells.FindNext(r)
If Not r Is Nothing Then
r = r.Value
End If
Wend
End If
End Sub

It looks like Excel is getting hung up on the "SearchFormat:=" portion of the code.