title: javascript prompt - adding variable in default text
body: <p>For javascript prompt:</p>
  
  <pre><code>prompt("Message", "default value in the text field");
  </code></pre>
  
  <p>is it possible to add a variable into the default value?</p>
  
  <p>For example: </p>
  
  <pre><code>var default = 'default value';
  prompt("Message", +default+"and other values");
  </code></pre>
  
  <p>The above example doesn't work as it shows 'NaN and other values' in the text field. I want the field to show 'default value and other values'. I'm wondering what's the right way to do it.</p>