var arrJHRQ=document.getElementById("txtstarttime").value.split('-'); //转成成数组,分别为年,月,日,下同
var arrJHWCSJ=document.getElementById("txtlasttime").value.split('-');
var dateJHRQ=new Date(parseInt(arrJHRQ[0]),parseInt(arrJHRQ[1])-1,parseInt(arrJHRQ[2]),0,0,0); //新建日期对象
var dateJHWCSJ=new Date(parseInt(arrJHWCSJ[0]),parseInt(arrJHWCSJ[1])-1,parseInt(arrJHWCSJ[2]),0,0,0);
if (dateJHRQ.getTime()>dateJHWCSJ.getTime())
{
alert('截止时间应大于开始时间');
return false;
}