webcam.js

var body = document.getElementsByTagName("body")[0];
body.innerHTML = 'Hello, World!';

navigator.getMedia = (navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia);

navigator.getMedia(
    // constraints
    {video:true, audio:false},

    // success callback
    function (mediaStream) {
        var video = document.getElementsByTagName('video')[0];
        video.src = window.URL.createObjectURL(mediaStream);
        video.play();
    },   
    //handle error
    function (error) {
        console.log(error);
    }
);