title: keeping a UIButton pressed(state selected/highlighted),until another button is pressed?
body: <p>I have 3 buttons at the bottom of my view controller, btn1 btn2 btn3, I'm using them instead of the tab bar as it is not possible to entirely customize a tab bar as per my requirements. </p>
  
  <p>Now the issue is, when btn1 is pressed, I want it to change its image, to a grey rectangle, instead of the normal state image. I have set the images for both states in the outlet I declared for the button, btn1Outlet, using the setimage and uicontrolstate properties of the outlet. </p>
  
  <p>The problem is, I can't keep the button selected until say either btn2 or btn3 is pressed. btn one changes to the selected state image only as long as it is pressed, the moment I leave it, it changes back to its normal state.</p>
  
  <p>How can I keep btn1's image as selected image until any of the other 2 buttons are pressed?</p>