title: How to display dynamically the previous month name
body: <p>I want to display the previous month name. My code is given below but it displays the index of that month. I want the name of that month. 
  According to this given code it dipslays the tool tip as "Balance up to 9", but I want to display "Balance up to September".
  How get the name of that month?</p>
  
  <pre><code>lblPreviousBalance.ToolTip = "Balance up to " + (DateTime.Now.Month - 1);
  </code></pre>