You can only get a valid patent if your invention is truly "novel", i.e. new. Apart from being novel the invention must also be inventive, for a standard patent or at least innovative, for an innovation patent.
Without getting too far off track I'll just point out that at present ACIP (i.e. the Advisory Council for Intellectual Property) is investigating whether or not the innovation patent system is working properly. Depending on the outcome of their investigations It could be that the innovation patent system will be either abolished or altered so that the test for "innovative" step is changed to the same test for "inventive step" that applies to standard patents.