因ios不兼容'-',所以需把'-'转换为'/',
function dateDiff(sDate1,sDate2){
var aDate, oDate1, oDate2, iDays
aDate = sDate1.split('-')
oDate1 = new Date(aDate[1]+'/'+aDate[2]+'/'+aDate[0])
aDate = sDate2.split('-')
oDate2 = new Date(aDate[1]+'/'+aDate[2]+'/'+aDate[0])
iDays = parseInt(Math.abs(oDate1-oDate2)/1000/60/60/24)
return iDays;
}