api/easyrtc.js
function extractVersion(uastring, expr, pos) {
  var match = uastring.match(expr);
  return match && match.length >= pos && parseInt(match[pos], 10);
}
function extractVersion(uastring, expr, pos) {
  var match = uastring.match(expr);
  return match && match.length >= pos && parseInt(match[pos], 10);
}
function extractVersion ( uastring , expr , pos ) { var match = uastring . match ( expr ) ; return match && match . length >= pos && parseInt ( match [ pos ] , 10 ) ; }
Extract browser version out of the provided user agent string.

@param {!string} uastring userAgent string.
@param {!string} expr Regular expression used as match criteria.
@param {!number} pos position in the version string to be returned.
@return {!number} browser version.
Extract browser version out of the provided user agent string .