Untitled

<html>
<head>
<title> Validation form </title>
</head>
<body>

<form id="validate">
Username: <input type="text" name="username" value="username"  id="userid"/><br><br>
Password: <input type="password" name="password" value="password" id="password" /><br><br>
Email: <input type="text" name="email-id" value="email-id" id="emailid"/><br><br>
<input type="button" id="submit" value="submit" onclick="validatefunction()"/>
</form>
<div>
<p id="invalid1"> </p>
<p id="invalid2"> </p>
<p id="invalid3"> </p>
</div>

<script language="javascript">
function validatefunction()
{
  var username;
  $username = document.getElementById('userid').value;
  var password;
  $password= document.getElementById("password").value;
  var email;
  $email= document.getElementById("emailid").value;

    var letternum = /^([0-9]|[a-z])+([0-9a-z]+)$/i;
    //var number = /[0-9]/;
  // var valid = number.test($username)  letter.test($username);
    var validemail= (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test($email));


    if(letternum)
    {
      document.getElementById('invalid1').innerHTML= " Username:" +$username;
    }
    else
    {
      document.getElementById('invalid1').innerHTML= " Incorrect username! " ;

     }

    if($password.length<8)
    {
       document.getElementById('invalid2').innerHTML= " Minimum length of password should be 8!" ;

    }
    else
    {
       document.getElementById('invalid2').innerHTML= "   Password:" +$password;

    }

    if(validemail)
    {
      document.getElementById('invalid3').innerHTML= "  Email-id: " +$email;
    }
    else
    {
      document.getElementById('invalid3').innerHTML= " Invalid email-id " ;

    }

}

</script>
</body>
</html>