javascript - Validating e-mail address -

i trying validate e-mail address using javascript. problem if statements aren't executing correctly. if delete 'else statement' code runs correnctly , page not load errors. if include 'else statement' else statement never executes , status bar says page loads errors. wondering if can find errors unable pick up?

<h4>example 4:</h4> <div style="border:3px dashed #aaa; width:200px;">     <div id="text">e-mail: <input id="email" onblur="verifyemail()"/></div>     <div id="verification" > </div> </div>  <script type="text/javascript"> function verifyemail(){     var email = document.getelementbyid("email").value;     var atpos=0;      var dotpos=0;      atpos = email.indexof("@");     dotpos = email.lastindexof(".");      if(atpos<=3 || dotpos<atpos+2 || dotpos+2>=email.length){         document.getelementbyid("verification").innerhtml = "invalid e-mail address";     }else{         document.getelementbyid("verification").innerhtml = "valid";     }  }    </script> 

try this

function validateemail(email) {      var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\ ".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-za -z\-0-9]+\.)+[a-za-z]{2,}))$/;     return re.test(email); }  

demo : here demo

or more simpler way

function validateemail(email)  {     var re = /\s+@\s+\.\s+/;     return re.test(email); } 

if using html5 try <input type="email"... please note. 1 works if input in form tag submit button , isn't handled js

<input type="email" placeholder="me@example.com">