function check_date()

{

var beginTime=$('#examStartTime').val();

var endTime=$('#examEndTime').val();

    var beginTimes = beginTime.substring(0, 10).split('-');

    var endTimes = endTime.substring(0, 10).split('-');

    beginTime = beginTimes[1] + '-' + beginTimes[2] + '-' + beginTimes[0] + ' ' + beginTime.substring(10, 19);

    endTime = endTimes[1] + '-' + endTimes[2] + '-' + endTimes[0] + ' ' + endTime.substring(10, 19);

    var a = (Date.parse(endTime) - Date.parse(beginTime)) / 3600 / 1000;

    if (a <= 0) {

        alert("开始时间必须小于结束时间");

        return false;

    } else {

        return true;

    }

}