判断日期是否能跨月查询的js代码

function checkDate(startDate, endDate, num, flag) { if(startDate == null || endDate == null) { popwin.info('提示','日期不可为空'); return false; } if(startDate == '' || endDate == '') { popwin.info('提示','请输入查询日期'); return false; } var start_date = startDate + "