Android : Multiple Tables In SQlite android

I wanna make a database in sqlite android ,and I wanna create 2 table in database ,and after that I wanna create tables dynamically. but my class DBAdapter just create one table and for other tables throws error "no such table" so what should I do for this? plz help me

    package com.example.asa;


import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DBAdapter {
    public static final String KEY_ROWID_con = "_id";
    public static final String KEY_NAME_con = "name";
    public static final String KEY_NUMBER_con = "number";
    private static final String TAG = "DBAdapter";
    private static final String DATABASE_TABLE_con = "contacts";

    private static final String DATABASE_NAME = "MyDB";
    private static final int DATABASE_VERSION = 2;

    private static final String DATABASE_CREATE_con =
        "create table contacts (_id integer primary key autoincrement, "
        + "name text not null, number text not null);";

    private final Context context;    

    private DatabaseHelper DBHelper;
    private SQLiteDatabase db;

    public DBAdapter(Context ctx) 
    {
        this.context = ctx;
        DBHelper = new DatabaseHelper(context);
    }

    private static class DatabaseHelper extends SQLiteOpenHelper 
    {
        DatabaseHelper(Context context) 
        {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) 
        {
            try {
                db.execSQL(DATABASE_CREATE_con);    
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) 
        {
            Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                    + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS chats");
            onCreate(db);
        }
    }    

    //---opens the database---
    public DBAdapter open() throws SQLException 
    {
        db = DBHelper.getWritableDatabase();
        return this;
    }

    //---closes the database---    
    public void close() 
    {
        DBHelper.close();
    }

    //---insert a contact into the database---
    public long insertContact(String name, String number) 
    {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_NAME_con, name);
        initialValues.put(KEY_NUMBER_con, number);
        return db.insert(DATABASE_TABLE_con, null, initialValues);
    }

    //---deletes a particular contact---
    public boolean deleteContact(long rowId) 
    {
        return db.delete(DATABASE_TABLE_con, KEY_ROWID_con + "=" + rowId, null) > 0;
    }

    //---retrieves all the contacts---
    public Cursor getAllContacts() 
    {
        return db.query(DATABASE_TABLE_con, new String[] {KEY_ROWID_con, KEY_NAME_con,
                KEY_NUMBER_con}, null, null, null, null, null);
    }

    //---retrieves a particular contact---
    public Cursor getContact(long rowId) throws SQLException 
    {
        Cursor mCursor =
                db.query(true, DATABASE_TABLE_con, new String[] {KEY_ROWID_con,
                KEY_NAME_con, KEY_NUMBER_con}, KEY_ROWID_con + "=" + rowId, null,
                null, null, null, null);
        if (mCursor != null) {
            mCursor.moveToFirst();
        }
        return mCursor;
    }

    //---updates a contact---
    public boolean updateContact(long rowId, String name, String number) 
    {
        ContentValues args = new ContentValues();
        args.put(KEY_NAME_con, name);
        args.put(KEY_NUMBER_con, number);
        return db.update(DATABASE_TABLE_con, args, KEY_ROWID_con + "=" + rowId, null) > 0;
    }

    //---Search Contact by String ---//
    public String Search(String str)
    {
        String [] columns = new String[]{ KEY_ROWID_con, KEY_NAME_con, KEY_NUMBER_con};
        return db.query(DATABASE_TABLE_con, columns, KEY_NAME_con + "=?", new String[] { str }, null, null, null).getString(0);
    }

    //---insert a contact into the database---

    }