JavaScript 实现开始与结束时间校验逻辑

<html>
<head>
<script>

 function checkTime(){

  var startTime = document.getElementById("_startTime").value.trim();
  var endTime = document.getElementById("_endTime").value.trim();
  if(startTime == "" || endTime == ""){
   alert("时间不能为空");
   return ;
  }
  var reg = /^((20|21|22|23|[0-1]\d)\:[0-5][0-9])(\:[0-5][0-9])$/;
  if(!reg.test(startTime) || !reg.test(endTime)){ 
   alert("您输入的时间格式不正确!"); 
   return ;
  }
  var startTimeArray = startTime.split(":");
  var endTimeArray = endTime.split(":");
  var startDate = new Date(startTimeArray[0],startTimeArray[1],startTimeArray[2]);
  var endDate = new Date(endTimeArray[0],endTimeArray[1],endTimeArray[2]);
  var start = startDate.getTime();
  var end = endDate.getTime();

  if (start >= end) {
   alert('开始时间不能大于结束时间');
   return ;
  }

  document.getElementById('form1').submit();

 }

</script>
</head>
<body>