title: Underline some characters in a String
body: <p>I have the following problem:</p>
  
  <p>My JavaScript code shows a display value this way:</p>
  
  <pre><code>d3.select("#" + uiElement).html("")
                          .append("span").attr("class", "displayvalue").html(stringToUse);
  </code></pre>
  
  <p>stringtoUse is the value to show, my issue is to underline that string, but some times, it's not required underline all the string but all except the first character of it.
  In your opinion what's the best way to do so?</p>