[Dilettante_Pro]

Без стрелочек и пр.

Email<input type='text' id = 'username'>
Password<input type='text' id = 'pass'>
<button>Тест</button>
<div id='result'></div>
<script>
var userEmail = document.getElementById("username"),
      userPass = document.getElementById("pass");
var regexp = new RegExp("^([a-z0-9_-]+\.)*[a-z0-9_-]+@[a-z0-9_-]+(\.[a-z0-9_-]+)*\.[a-z]{2,6}$");
var regexpP = new RegExp("^[a-zA-Z0-9!@#$%^&*]{6,16}$");

document.querySelector('button').onclick = function() {
        result.textContent = validate();
}
function validate() {
   var resultE = false, resultP = false;
   if(!regexp.test(userEmail.value)) {
       userEmail.style.border = "2px solid red";
   } else {
       userEmail.style.border = "2px solid green";
       resultE = true;
   }
   if(!regexpP.test(userPass.value)) {
       userPass.style.border = "2px solid red";
   } else {
       userPass.style.border = "2px solid green";
       resultP = true;
   }
    return resultP && resultE;
}
</script>