error while opening sqlite database from myown path in android

I have created a sampleDb.sqlite and copied that db in the asset folder. When I try to open it, it gives me the following error in logcat:

03-09 07:20:50.991: E/SQLiteLog(11307): (14) cannot open file at line 30191 of [00bb9c9ce4]
03-09 07:20:50.991: E/SQLiteLog(11307): (14) os_unix.c:30191: (2) open(//data/data/com.example.dietanimation/databases/sampleDb.sqlite) - 
03-09 07:20:51.181: E/SQLiteDatabase(11307): Failed to open database 'data/data/com.example.dietanimation/databases/sampleDb.sqlite'.
03-09 07:20:51.181: E/SQLiteDatabase(11307): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at com.example.dietanimation.DBhelper.isDatabaseAvailable(DBhelper.java:71)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at com.example.dietanimation.DBhelper.<init>(DBhelper.java:34)
03-09 07:20:51.181: E/SQLiteDatabase(11307):    at com.example.dietanimation.MainActivity.onCreate(MainActivity.java:67)

and following is my code

public class DBhelper extends SQLiteOpenHelper 
{
    static String DBName="sampleDb.sqlite";
    String Table_Name="diet_tbl";
    public final static int version=1;
     public static String DB_PATH=null;
     public SQLiteDatabase myDatabase=null;
     private Context myContext=null;
     SQLiteDatabase dbHelper;

    public DBhelper(Context context) {
        super(context, DBName, null, version);
        // TODO Auto-generated constructor stub
        DB_PATH="data"+File.separator+"data"+File.separator+context.getPackageName()+File.separator+"databases"+File.separator;
        this.myContext=context;
        Log.d("Debug"," Point 2");
        boolean checkDb= isDatabaseAvailable();

        if(checkDb){

        }else{
            this.getReadableDatabase();
            try{
            Log.d("Debug"," Point 5");
              copyTheDatabase();
            }catch(IOException e){
                Log.d("Debug"," Point 6");
                throw new Error("Error Coping database");
            }
        }   
    }
    private void copyTheDatabase() throws IOException {
        // TODO Auto-generated method stub
        InputStream myInput=myContext.getAssets().open("sampleDb.sqlite");
        String outFileName=DB_PATH+DBName;
        Log.d("Debug"," Point 7 with File");
        OutputStream myOutput=new FileOutputStream(outFileName);
        byte[] buffer=new byte[1024];
        int length;
        while((length=myInput.read(buffer))>0){
            myOutput.write(buffer,0,length);
        }
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }
    private boolean isDatabaseAvailable() {
        // TODO Auto-generated method stub

        SQLiteDatabase checkDB=null;

        try{
            String myPath=DB_PATH+DBName;
            checkDB=SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

        }catch(SQLiteException e){
            Log.d("Debug"," Point 3"); 
        }
        if(checkDB!=null){
             checkDB.close();
         }
        Log.d("Debug"," Point 4");  
            return checkDB!=null ?true:false;   
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
    }
please help me asap.