var input1 = $('#input1');

var input2 = $('#input2');

​

var source = Rx.Observable.amb(

  Rx.Observable.fromEvent(input1, 'click').map(()=>'one'),

  Rx.Observable.fromEvent(input2, 'click').map(()=>'two')

);

​

var subscription = source.subscribe(

    function (x) {

        console.log(x);

    },

    function (err) {

        console.log('Error: ' + err);   

    },

    function () {

        console.log('Completed');   

    });