<script type="text/javascript">
    function validateUser(){
        var username = document.getElementById("username");
        var password = document.getElementById("password");
        var ref = new Firebase("https://sweltering-heat-6293.firebaseio.com");
        ref.authWithPassword({
          email    : username.value,
          password : password.value
        }, function(error, authData) {
          if (error) {
            document.getElementById('login_form').action  = "index.html";
            console.log("Login Failed!", error);

          } else {
            console.log("Authenticated successfully with payload:", authData);
          }
        });
    }

</script>

<label for="password">
            <span>Enter Password</span><input type="password" name="password" value = "" id = "password" required="true" />
        </label>

        <label>
            <span>&nbsp;</span><input type="submit" value="Login" onclick="validateUser()"/>
        </label>

    </form>