title: How to implement onClick in my activity
body: <p>I have list of passwords (strings) in a database.
  In my activity i put EditText (the user will write there his/her password) and a button.
  How i can implement onClick for the button that will check if the password are in the system (in the list)?
  <a href="https://i.stack.imgur.com/nptI4.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nptI4.jpg" alt="in the image you can see part of the xml code"></a></p>