title: Alphanumeric email validation in javascript
body: <p>I'm using a regex below to validate email to accept alphanumeric characters. It works in the following cases</p>
  
  <p>1) Must contain atleast one alphabets
  2) allow alphanumeric
  3) allow special characters <code>.-and _</code></p>
  
  <p><strong>Regular Expression:</strong></p>
  
  <p><code>/^([a-zA-Z0-9])(([a-zA-Z0-9])*([\._-])?([a-zA-Z0-9]))*@(([a-zA-Z0-9\-])+(\.))+([a-zA-Z]{2,4})+$/i</code></p>
  
  <p><strong>Cases:</strong></p>
  
  <p><code>1111@gmail.com - allow</code> </p>
  
  <p><code>aaaa@gmail.com  - allow</code></p>
  
  <p><code>aa1_aa@gmail.com - allow</code></p>
  
  <p><strong>Output expected:</strong></p>
  
  <p><code>1111@gmail.com - not allow because it does not contain alphabets before @</code></p>
  
  <p><code>aaaa@gmail.com  - allow</code></p>
  
  <p><code>a1@gmail.com  - allow</code></p>
  
  <p><code>1a@gmail.com  - allow</code></p>
  
  <p><code>aa1_aa@gmail.com - allow</code></p>
  
  <p>Hers is jsfiddle <a href="http://jsfiddle.net/JCRcQ/97/" rel="nofollow">Demo</a></p>