title: Regex Letters, Numbers, Dashes, and Underscores
body: <p>Im not sure how I can achieve this match expression.  Currently I am using, </p>
  
  <pre><code>([A-Za-z0-9-]+)
  </code></pre>
  
  <p>...which matches letters and numbers.  I would also like to match on dashes and underscores in the same expression.  Anyone know how?</p>
  
  <p>I would like to be able to match <strong>product_name</strong> and <strong>product-name</strong></p>