title: Click on button keeping focus in textbox
body: <p>I am trying to make a simple calculator. I have buttons to write numbers in text boxes.</p>
  
  <p>What I need to do is that when I choose text box 1 and click on buttons, numbers should be inputted in textbox 1 and when I choose textbox 2 and click on buttons, numbers should be inputted in textbox 2. </p>
  
  <p>I have tried many different ways but nothing worked right, so if you have an idea how to solve this problem please write. Thx!</p>
  
  <p><a href="https://i.stack.imgur.com/8GePY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8GePY.png" alt="enter image description here"></a></p>