一段能在Windows2000下正常，在Windows98下却会出内存错误的代码，请大家指点！谢谢啦！ (0分)

function Getbm(Text:String):String;
var
   bmVal,RetVal: integer;
   MemMapFile:TMemMapFile;// 用来文件的内存映射
   SearchRec:TSearchRec;
   FoundStr:pchar;
   FName:String;
begin
    FoundStr:=nil;
    RetVal:=FindFirst(ExtractFilePath(Paramstr(0))+'*.bm',faAnyFile,SearchRec);
    try
       while (RetVal=0) and (FoundStr=nil) do
       begin
          FName:=ExtractFilePath(Paramstr(0))+SearchRec.Name;
          bmVal:=StrToInt(ExtractFileName(FName)[1]);
          MemMapFile:=TMemMapFile.Create(FName,fmOpenRead,0,True);//将查找到的文件内存映射
          try
          FoundStr:=StrPos(Pchar(MemMapFile.Data),Pchar(Text));//错误应该是在这行，因为如果我注释掉这行就正常
          Result:=copy(StrPas(FoundStr),1,bmVal+Length(Text));
          RetVal:=FindNext(SearchRec);
          finally
          MemMapFile.Free;
          end;
        end;
      finally
          FindClose(SearchRec);
      end;
end;