public bool Exists(string fileName)
{
string altSeparator = fileName.Replace('/', '\\');
return Archive.Entries.Any(e => e.FullName.Equals(fileName, StringComparison.InvariantCultureIgnoreCase))
|| Archive.Entries.Any(e => e.FullName.Equals(altSeparator, StringComparison.InvariantCultureIgnoreCase));
}