title: how can I get the selected value of radio button?
body: <p>I am not matlab programmer but I need to create an interface using matlab!
  This qusetion should be very easy for matlab programmers :) </p>
  
  <p>I have an interface which contains radio button group panel "OperationPanel"
  ,4 radioButtons inside it which names are "addBtn, subBtn, divBtn, mulBtn" and I have command button, I want when I click over the button to get the value of the selected radioButton </p>
  
  <p>What is the commad I should use ? I google it and found that if I make</p>
  
  <pre><code>get(handles.NewValue,'Tag');
  </code></pre>
  
  <p>I tired it but it doesn't work!! Can I hava some help!</p>