How To Put Array Populated By Other Activity To Arraylist

I am developing some application for android and i have problem.

I push data with button click from another activity with intent to string of first activity, and i put from that string these data to listview by a adapter, and it is all ok, i mean i see on listview that data, but when i want to add new item in listview by click of button of second activity, i mean do again same thing, there is a problem: that data i push by a second button click replaces first button click data, and i want to add that data under first data in another listview row?

here is code of activity where is a listview:

package com.example.kupi;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import android.R.array;
import android.app.Activity;

[Code] .....