title: systam error at replace line in javascript
body: <p>I am new to javascript, i am trying to call function while login time, but i am getting error in browser console in IE11.</p>
  
  <pre><code>function myLogin(){
      alert("login alert89");
      var str =document.getElementById("j_password").value;       
      var enc = window.btoa(str);
  
  var chars = {'a':'b','b':'c','c':'a'};
  var new1;
  new1 = enc.replace(/[abc]/g, m =&gt; chars[m]);
      document.getElementById("j_password").value=new1;
  
  }
  </code></pre>
  
  <p>I am getting <code>systam error</code> at <code>new1 = enc.replace(/[abc]/g, m =&gt; chars[m])</code> line. But is working in chrome. What's wrong in my code?</p>