Why if and else both of condition are getting executed in javascript used with firebase database?

var loginDB = firebase.database().ref("login-demi");

document.getElementById("login").addEventListener('submit', perform);
function perform(e) {
  e.preventDefault();
  var vname = document.getElementById("namNew").value;
  var vpassword = document.getElementById("pswd").value;
  loginDB.orderByChild("name" + "password").on("child_added", function (data) {
    var nam = data.val().name;
    var pss = data.val().password;
    if (nam == vname && pss == vpassword) {
      console.log(pss);
    } else {
      console.log(vname);
    }
  });
}

<div class="alert">Logging In!</div>
<div class="alert1">Try Again</div>
<div class="InputBox">
   <input type="text" id="namNew" placeholder="Name">
</div>
<div class="InputBox">
   <input type="password" id="pswd" placeholder="Password">
</div>