我在文本框中取不到值啊

package com.ab.jiugongge;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Toast;

public class MainActivity extends Activity {

private Button buttonlog;

private EditText et1;

private EditText et2;

private String username;

private String password="";

private String x = "x";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

buttonlog = (Button)findViewById(R.id.button1);

et1 = (EditText) findViewById(R.id.editText1);

et2 = (EditText) findViewById(R.id.editText2);

username = et1.getText().toString();

password = et2.getText().toString();

x="xx";

buttonlog.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View arg0) {

// TODO Auto-generated method stub

if("qiezi".equals(username)&&"217".equals(password)){

Intent intent = new Intent(MainActivity.this, JActivaty.class);

startActivity(intent);

}else{

Toast.makeText(MainActivity.this, "登录失败"+username+password+x,1).show();

}

}

});