Open first application from 2nd application which is close

Below is the code i am using to open other application from with in my application.

 Intent intent = new Intent(Intent.ACTION_MAIN);    
    intent.setComponent(newComponentName("com.demo.iTemp.activity","com.demo.iTemp.activity.SplashActivity"));

Now with this I am able to open the application. But I am not able to get back to the main application from 2nd application. For example if I press back button it will exit and will not open Ist applicaton. can any body guide me how to open 1st from 2nd again.