function _throttling(fn,wait,mustRun){

                var time=null;

                var startTime= new Date()

                return function(){

                    clearTimeout(time)

                    time=null;

                    var endTime=new Date();

                    if(endTime-startTime>=mustRun){

                        startTime=endTime;

                        fn();

                    }

                    else{

                        time=setTimeout(fn,wait)

                    }

                }

            }

_throttling(resetH,50,33)