text: window.RTCPeerConnection = window.RTCPeerConnection || window.webkitRTCPeerConnection || window.mozRTCPeerConnection;
  window.RTCIceCandidate = window.RTCIceCandidate || window.mozRTCIceCandidate || window.webkitRTCIceCandidate;
  window.RTCSessionDescription = window.RTCSessionDescription || window.mozRTCSessionDescription || window.webkitRTCSessionDescription;
  window.URL = window.URL || window.mozURL || window.webkitURL;
  window.navigator.getUserMedia = window.navigator.getUserMedia || window.navigator.webkitGetUserMedia || window.navigator.mozGetUserMedia;
  
  