SQLite Exception: near ")": syntax error (code 1 SQLITE_ERROR), don't know what's wrong

I'm trying to use SQlite but this error comes up:

E/SQLite Exception: near ")": syntax error (code 1 SQLITE_ERROR): , while compiling: CREATE TABLE IF NOT EXISTS contact ( _id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, organization TEXT, phone INTEGER, address TEXT, email TEXT, web_ad TEXT, inf TEXT, birthday TEXT NULL, )

And I guess it should be this part of my code:

    public static final String SQL_CREATE_ENTRIES = "" +
        "CREATE TABLE IF NOT EXISTS " + ContactHelper.TABLE +" ( "+
        ContactHelper._ID +" INTEGER PRIMARY KEY AUTOINCREMENT, "+
        ContactHelper.COL_NAME +" TEXT, "+
        ContactHelper.COL_ORGANIZATION +" TEXT, "+
        ContactHelper.COL_PHONE +" INTEGER, "+
        ContactHelper.COL_ADDRESS +" TEXT, "+
        ContactHelper.COL_EMAIL + " TEXT, " +
        ContactHelper.COL_WEB + " TEXT, " +
        ContactHelper.COL_INF + " TEXT, " +
        ContactHelper.COL_BIRTH + " TEXT NULL, " +
        " ) ";

it's odd because at first SQL_CREATE_ENTRIES was like below and there was no error, once I added a couple of more columns, that error came up.

    public static final String SQL_CREATE_ENTRIES = "" +
        "CREATE TABLE IF NOT EXISTS " + ContactHelper.TABLE +" ("+
        ContactHelper._ID +" INTEGER PRIMARY KEY AUTOINCREMENT, "+
        ContactHelper.COL_NAME +" TEXT, "+
        ContactHelper.COL_ORGANIZATION +" TEXT NULL, "+
        ContactHelper.COL_PHONE +" INTEGER, "+
        ContactHelper.COL_ADDRESS +" TEXT NULL"+
        ")";

I've looked at similar questions, they all say that there should be a space before and after words but it didn't work.