title: how can I join two regex into one?
body: <p>I have two regex that I need to join into one as I am using the <a href="https://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.regularexpressionattribute%28v=vs.110%29.aspx" rel="nofollow noreferrer">RegularExpressionAttribute</a> in ASP.NET and it does not allow multiple instances.</p>
  
  <p>How can I join the following two regex into one?</p>
  
  <pre><code>.*?@(?!.*?\.\.)[^@]+$
  [\x00-\x7F]
  </code></pre>
  
  <p>the first one checks that there are not 2 consecutive dots in the domain part of an email and the second regex checks that all characters are ascii</p>
  
  <p>I thought it might have been as easy as joining them together like <code>(.*?@(?!.*?\.\.)[^@]+$)([\x00-\x7F])</code> but this does not work</p>
  
  <p>Here is <a href="https://stackoverflow.com/questions/29814935/regex-to-fail-email-domain-with-two-consecutive-dots">link</a> to previous post relating to this problem</p>
  
  <p><strong>EDIT</strong>: I am decorating an string property of my viewmodel using reglarexpression attribute and this gets rendered into javascript using unobtrusive therefore it has to validate using javascript. I failed to mention this in my initial post</p>