title: Javascript multiple email regexp validation
body: <p>Normally validation of simple email is:</p>
  
  <pre><code>/^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/
  </code></pre>
  
  <p>This will validate email like <code>test@test.com</code></p>
  
  <p>But how to validate if email is multiple?</p>
  
  <pre><code>entry 1: test@test.com, test1@test.com, test2@test.com
  entry 2: test@test.com , test1@test.com , test2@test.com
  entry 3: test@test.com, test1@test.com , test2@test.com
  entry 4: test@test.com
  </code></pre>
  
  <p>This emails is a possible entries that user will input. Also expect thier is 2 or 3 or 4 or more emails sometimes.</p>
  
  <p>Thanks for the answers.</p>