android.database.sqlite.SQLiteException: near "Details": syntax error (code 1):

I'm getting this error for my database:

android.database.sqlite.SQLiteException: near "Details": syntax error (code 1): the Line of code which is causing the error is in the onCreate method I'm wondering if its something small I'm missing? I've inserted the commas and the same error is coming up.

DatabaseHandler.java

public class DatabaseHandler extends SQLiteOpenHelper {
//DATABASE VERSION
private static final int DATABASE_VERSION = 1;
//DATABASE NAME
private static final String DATABASE_NAME = "Appdatabase";
//TABLE NAMES
private static final String TABLE_REGISTER = "Register Details";
private static final String TABLE_PRODUCT = "Product Details";
//COMMON COLUMN NAMES
private static final String KEY_USERID = "UserID's";
private static final String KEY_PRODUCTID = "ProductID's";
//REGISTER COLUMN NAMES
private static final String KEY_USERNAME = "Username";
private static final String KEY_PASSWORD = "Password";
private static final String KEY_AGE = "Age";
private static final String KEY_GENDER = "Gender";
private static final String KEY_HEIGHT = "Height";
private static final String KEY_STRTWEIGHT = "StartWeight";
private static final String KEY_CURRWEIGHT = "CurrentWeight";
private static final String KEY_WEIGHTCHANGE = "WeightChange";
private static final String KEY_MONCAL = "MondayCalories";
private static final String KEY_TUESCAL = "TuesdayCalories";
private static final String KEY_WEDCAL = "WednesdayCalories";
private static final String KEY_THURCAL = "ThursdayCalories";
private static final String KEY_FRICAL = "FridayCalories";
private static final String KEY_SATCAL = "SaturdayCalories";
private static final String KEY_SUNCAL = "SundayCalories";
private static final String KEY_WEEKLYBUDGET = "WeeklyBudget";

//PRODUCT COLUMN NAMES
private static final String KEY_ITEMNAME = "ItemName";
private static final String KEY_ITEMPRICE = "ItemPrice";
private static final String KEY_ITEMCALORIE = "ItemCalories";


public DatabaseHandler(Context context){
    super(context,DATABASE_NAME, null, DATABASE_VERSION);
}


public void onCreate(SQLiteDatabase db){
    String CREATE_PRODUCT_TABLE = "CREATE TABLE " + TABLE_PRODUCT + "(" +
            KEY_PRODUCTID + " INTEGER PRIMARY KEY, " +
            KEY_ITEMNAME + " TEXT, " +
            KEY_ITEMPRICE + " DOUBLE, " +
            KEY_ITEMCALORIE + " DOUBLE " + ")";

    String CREATE_REGISTERDETAILS_TABLE = "CREATE TABLE " + TABLE_REGISTER + " ( "+ KEY_USERID + " INTEGER PRIMARY KEY , " + KEY_USERNAME + " TEXT, " +
            KEY_PASSWORD + " TEXT, " +
            KEY_GENDER + " TEXT, " +
            KEY_HEIGHT + " DOUBLE, " +
            KEY_CURRWEIGHT + " DOUBLE, " +
            KEY_STRTWEIGHT + " DOUBLE, " +
            KEY_WEIGHTCHANGE + " DOUBLE, " +
            KEY_AGE + " INTEGER, " +
            KEY_MONCAL + " DOUBLE, " +
            KEY_TUESCAL + " DOUBLE, " +
            KEY_WEDCAL + " DOUBLE, " +
            KEY_THURCAL + " DOUBLE, " +
            KEY_FRICAL + " DOUBLE, " +
            KEY_SATCAL + " DOUBLE, " +
            KEY_SUNCAL + " DOUBLE, " +
            KEY_WEEKLYBUDGET + " DOUBLE );";
    //CREATING REQUIRED TABLES
    db.execSQL(CREATE_REGISTERDETAILS_TABLE);
    db.execSQL(CREATE_PRODUCT_TABLE);

}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
    //ON UPGRADE DROP THE OLDER TABLES
    db.execSQL("DROP TABLE IF EXISTS" + TABLE_REGISTER);
    db.execSQL("DROP TABLE IF EXISTS" + TABLE_PRODUCT);
    onCreate(db);
}