SMS pager app - trying to recognize text and setting sound

Hello everyone!

I am new to AppInventor and want to create a simple app, that will notify user with a loud sound, when a SMS with certain text in it is recived - or do nothing if triger is not true.
Till now all I got is sound playing no matter what the SMS text was or just closing the app after SMS recived.
Here are my blocks and hope you help me find a solution.

Your code does not start the Sound component. Use the call Sound.Start procedure under the when MessageReceived method.

You also may want to stop the component if you are changing screens.