title: How to avoid input string/StringBuilder in an incorrect format error in C#
body: <p>I'm using a string builder to append text to string.</p>
  
  <pre><code>StringBuilder content = new StringBuilder(GetStartHTML("installation",string.Empty));
  .......
  content.AppendFormat("&lt;td&gt;" + idcStepEntity.Comment + "&lt;/td&gt;");
  </code></pre>
  
  <p>Unfortunetly i cannot control what comes in from the customer as comment, so i they write something like : <em>comment { commment] comment</em> (and they often do) i get string was not in a correct format error.
  That mean i should not use a StringBuilder here? Should i use<code>string += otherstring</code> or is there any other String class that can bu usefull here?</p>
  
  <p>Thanks in advance :)</p>