change the way that judging js function's existence
change the way that judging js function's existence

chieryw/JSPatch,bang590/JSPatch,chieryw/JSPatch,chieryw/JSPatch,bang590/JSPatch,rob2468/JSPatch,bang590/JSPatch,ipinka/JSPatch,chieryw/JSPatch,ipinka/JSPatch,ipinka/JSPatch,qskycolor/JSPatch,bang590/JSPatch,ipinka/JSPatch,rob2468/JSPatch,ipinka/JSPatch,rob2468/JSPatch,qskycolor/JSPatch,rob2468/JSPatch,chieryw/JSPatch,bang590/JSPatch