android add more button like that in the contacts application

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http://stackoverflow.com – Am working with an application that contains a form filling with a contact information, and the contact may has many phone numbers, I added many edit texts to enter those phones and a button near the first one which show the next edit text when the user press on it The problem is I don't know what to write inside the on click listener of that button, I only want to show and hide the edit texts such that in the contacts application (HowTos)