How can I get product id corrosponding with the item in listview with search.

import java.util.ArrayList;
import java.util.HashMap;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {
	
	// List view
	private ListView lv;
	
	// Listview Adapter
	ArrayAdapter<String> adapter;
	
	// Search EditText
	EditText inputSearch;
	
	
	// ArrayList for Listview
	ArrayList<String> productList = new ArrayList<String>();
	ArrayList<String> ProdIds = new ArrayList<String>();
	public static String selectedProdId;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // Listview Data
        productList.add("Item1");
        productList.add("Item2");
        productList.add("Item3");
        productList.add("Item4");
        productList.add("Item5");
        
        // ListView Id that referes to items for ex:  Item1 having Prodid=1,item5>Prodid=5 and so on..
        ProdIds.add("1");
        ProdIds.add("2");
        ProdIds.add("3");
        ProdIds.add("4");
        ProdIds.add("5");
             
        
        lv = (ListView) findViewById(R.id.list_view);
        inputSearch = (EditText) findViewById(R.id.inputSearch);
        
        
        // Adding items to listview
        adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.product_name, productList);
        lv.setAdapter(adapter);
        
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
					long arg3) {
				// TODO Auto-generated method stub
				selectedProdId= ProdIds.get(arg2);
			    Toast.makeText(MainActivity.this, selectedProdId ,Toast.LENGTH_SHORT).show();
	
			}
		});
        
        
        /**
         * Enabling Search Filter
         * */
        inputSearch.addTextChangedListener(new TextWatcher() {
			
			@Override
			public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
				// When user changed the Text
				MainActivity.this.adapter.getFilter().filter(cs);	
			}
			
			@Override
			public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
					int arg3) {
				// TODO Auto-generated method stub
				
			}
			
			@Override
			public void afterTextChanged(Editable arg0) {
				// TODO Auto-generated method stub							
			}
		});
    }
    
}