var ref = new Firebase("https://stackoverflow.firebaseio.com/27137492");

​

var USERS = 'https://stackoverflow.firebaseio.com/27137492/users';

var reqestEmail = "test1@test.com";

​

console.log(reqestEmail); // proper email here

new Firebase(USERS)

    .orderByChild('email')

    .startAt(reqestEmail)

    .endAt(reqestEmail)

    .once('value', function(snap){

         var foundUser = snap.val();

         console.log(foundUser) // output is correct

    });

​

var data = {

  "users" : {

    "simplelogin:001" : {

      "email" : "test1@test.com",

      "mobile" : "+15555551001"

    },

    "simplelogin:002" : {

      "email" : "test2@test.com",

      "mobile" : "+15555551001"

    },

    "simplelogin:003" : {

      "email" : "test3@test.com",

      "mobile" : "+15555551003"

    }

  }

};

//ref.set(data);

​

​