how can i close an app launched from another app?

I used an external player in my app to play a fil开发者_运维技巧e.But after playing when i click the back button it is asking for saving the url.But in my app it must not be saved how to do that. Please help me.I tried closing the player forcebly but it not worked. Thanks in advance

Generally speaking, you cannot control other applications that you have launched. If you need that type of control, you will have to implement all the functionality in your own application.