Untitled

<html>
    <head>
        <meta charset="utf-8" />
        <title>Java Script 2</title>
    </head>
    <body>
    <div id="loginForm">
        <form name="userLogin">
        <input type="text" name="userName" />
        <input type="password" name="userPass" />
        <input type="button" name="login" value="Login" />
        </div>
        <script src = "question_2.js"></script>
        </form>
    </div>
    </body>
</html>

var submit = document.getElementById("login");

if(submit!="null"){
submit.addEventListener("click",getLogin);
}

 function getLogin(){
    var nameData = "admin";
    var passData = "admin";
    var userName = document.userLogin.userName.value;
    var pass = document.userLogin.userPass.value;


    if(userName.compareTo(nameData) && pass.compareTo(passData)){
        replace.textContent("Hello there " + nameData);
    }
    else{
        document.write("Try again");
    }
}

<input type="button" name="login" value="Login" />

if(submit!="null")

if(submit!==null)

var submit = document.getElementById("login");

if(submit){
submit.addEventListener("click",getLogin);
}