}
	switch checkIfNoneMatch(w, r) {
	case condFalse:
		if r.Method == "GET" || r.Method == "HEAD" {
			writeNotModified(w)
			return true, ""
		} else {
			w.WriteHeader(StatusPreconditionFailed)
			return true, ""
		}
	case condNone:
		if checkIfModifiedSince(r, modtime) == condFalse {
			writeNotModified(w)
			return true, ""
		}
	}

	rangeHeader = r.Header.get("Range")