Hi In My Application I have username and password and login button.click the login submit button without checking validations and empty fields also moving to next activity.

I want to check whether the username is required and password required clicking login button move to next activity.

Login.java

public class Login extends Activity {
    Button login;
    private static final Pattern USERNAME_PATTERN = Pattern
            .compile("[a-zA-Z0-9]{1,250}");
    private static final Pattern PASSWORD_PATTERN = Pattern
            .compile("[a-zA-Z0-9+_.]{4,16}");
    EditText usname,pword;
    TextView tv;
    String result=null;
    HttpPost httppost;
    StringBuffer buffer;
    HttpResponse response;
    HttpClient httpclient;
    CheckBox mCbShowPwd;
    List<NameValuePair> nameValuePairs;
    ProgressDialog dialog = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);
        login = (Button)findViewById(R.id.login);  
        usname = (EditText)findViewById(R.id.username);
        pword= (EditText)findViewById(R.id.password);
        mCbShowPwd = (CheckBox) findViewById(R.id.cbShowPwd);
       mCbShowPwd.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                // checkbox status is changed from uncheck to checked.
                if (!isChecked) {
                        // show password
                    usname.setTransformationMethod(PasswordTransformationMethod.getInstance());
                } else {
                        // hide password
                     pword.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
                }
            }
        });
       login.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                final String username = usname.getText().toString();
                final String password = pword.getText().toString();
                if (username.equals("") || password.equals("")) {
                    if (username.equals("")) {
                        Toast.makeText(Login.this, "ENTER USERNAME",
                                Toast.LENGTH_LONG).show();
                    }
                    if (password.equals("")) {
                        Toast.makeText(Login.this, "ENTER PASSWORD",
                                Toast.LENGTH_LONG).show();
                    }
                } else {
                    if (!CheckUsername(username)) {
                        Toast.makeText(Login.this, "ENTER VALID USERNAME",
                                Toast.LENGTH_LONG).show();
                    }
                    if (!CheckPassword(password)) {
                        Toast.makeText(Login.this, "ENTER VALID PASSWORD",
                                Toast.LENGTH_LONG).show();
                    }
                }
                final String queryString = "username=" + username + "&password="
                        + password;
                String result = DatabaseUtility.executeQueryPhp("login",queryString);
                 Intent i = new Intent(getApplicationContext(), Home.class);
                    startActivity(i);
                        }
                      });
            }
            private boolean CheckPassword(String password) {
                return PASSWORD_PATTERN.matcher(password).matches();
            }
            private boolean CheckUsername(String username) {
                return USERNAME_PATTERN.matcher(username).matches();
            }