안드로이드 회원가입 php 연동 도와 주세요!!ㅜ.ㅜ

Question

package com.example.administrator.yewsss;

import android.app.ProgressDialog;
import android.os.Bundle;
import android.os.Looper;
import android.os.StrictMode;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import java.util.ArrayList;
import java.util.List;


public class JoinActivity extends ActionBarActivity {

    Button JoinBtn,LoginBtn1;
    EditText edtId,edtPw,edtName,edtMail;
    HttpPost httppost;
    HttpResponse response;
    HttpClient httpclient;
    List<NameValuePair> nameValuePairs;
    ProgressDialog dialog = null;

    private static final String SERVER_ADDRESS = "http://아이피주소";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_join);

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

        edtId=(EditText)findViewById(R.id.edtId);
        edtPw =(EditText)findViewById(R.id.edtPw);
        edtName=(EditText)findViewById(R.id.edtName);
        edtMail=(EditText)findViewById(R.id.edtMail);
        JoinBtn =(Button)findViewById(R.id.JoinBtn);
        LoginBtn1=(Button)findViewById(R.id.LoginBtn1);

        JoinBtn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {

                if (edtId.getText().toString().equals("") || edtPw.getText().toString().equals("") || edtName.getText().toString().equals("") || edtMail.getText().toString().equals("")) {
                    Toast.makeText(JoinActivity.this, "입력오류입니다", Toast.LENGTH_SHORT).show();
                    return;
                }//항목중 하나라도 입력이 안되었을때


                dialog = ProgressDialog.show(JoinActivity.this, "",
                        "이런 ..", true);
                new Thread(new Runnable() {
                    public void run() {
                        Looper.prepare();
                        join();
                        Looper.loop();
                    }
                }).start();
            }
        });


    }

    void join(){
        try{
            httpclient=new DefaultHttpClient();
            httppost= new HttpPost("http://아이피주소/PHP파일경로/ex1.php");//"C:/APM_Setup/htdocs/web_server/lostdog";
            nameValuePairs = new ArrayList<NameValuePair>(4);
            nameValuePairs.add(new BasicNameValuePair("Id",edtId.getText().toString()));
            nameValuePairs.add(new BasicNameValuePair("Pw",edtPw.getText().toString()));
            nameValuePairs.add(new BasicNameValuePair("Name",edtName.getText().toString()));
            nameValuePairs.add(new BasicNameValuePair("Mail",edtMail.getText().toString()));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            response=httpclient.execute(httppost);
            ResponseHandler<String> responseHandler = new BasicResponseHandler();
            final String response = httpclient.execute(httppost, responseHandler);
           runOnUiThread(new Runnable() {
                public void run() {
                    dialog.dismiss();
                }
            });

          Toast.makeText(JoinActivity.this, "WELCOME", Toast.LENGTH_SHORT).show();
           /* Intent iIntent = new Intent(JoinActivity.this, LoginActivity.class);
            startActivity(iIntent);
            finish();*/


        }catch(Exception e){
            dialog.dismiss();
            System.out.println("Exception : " + e.getMessage());
        }
    }

}

안녕하세요

안드로이드를 배운지 얼마 안되 학생입니다

회원가입을 만들어봤는데요 ㅜ.ㅜ

회원가입버튼을 누르면 화면이 멈춥니다

물론 디비에도 데이터가 안들어가구요 ..

뭐가 문제일까요 ㅜ.ㅜ

부탁드립니다!!ㅜ.ㅜ