public void logIn(View v){
        boolean validationError = false;
        String username = username_text.getText().toString();
        String password = password_text.getText().toString();

        if(isEmpty(username_text)){
            validationError=true;
            Toast toast = Toast.makeText(getApplicationContext(),"Enter your username",Toast.LENGTH_SHORT);
            toast.show();
        }
        if(isEmpty(password_text)){
            validationError=true;
            Toast toast = Toast.makeText(getApplicationContext(),"Enter your password",Toast.LENGTH_SHORT);
            toast.show();
        }

        if(!validationError){
            /**
             * Log In User:
             */
            Backendless.UserService.login(username, password, new AsyncCallback<BackendlessUser>() {
                @Override
                public void handleResponse(BackendlessUser response) {

                    Intent intent = new Intent(MainActivity.this, LoadingActivity.class);
                    startActivity(intent);
                }

                @Override
                public void handleFault(BackendlessFault fault) {
                    if(fault.getCode().equals("3003")){
                        Toast toast = Toast.makeText(getApplicationContext(),"Password does not match username",Toast.LENGTH_SHORT);
                        toast.show();
                    }else if(fault.getCode().equals("3087")){
                        Toast toast = Toast.makeText(getApplicationContext(),"This account still awaits confirmation. Check your email inbox",Toast.LENGTH_SHORT);
                        toast.show();
                    }
                    else{
                        System.out.println("ERROR ON LOGIN" + fault.getCode() + " " + fault.getMessage());
                    }
                }
            },true);

        }


    }