js判断两日期相差的天数

function checkTime() {
        var sDate1 = $("#inputOrderTimeStart").val();
        var sDate2 = $("#inputOrderTimeEnd").val();
        var aDate, oDate1, oDate2, iDays
        aDate = sDate1.split("-")
        oDate1 = new Date(aDate[1] + '-' + aDate[2] + '-' + aDate[0]) //转换为12-18-2002格式
        aDate = sDate2.split("-")
        oDate2 = new Date(aDate[1] + '-' + aDate[2] + '-' + aDate[0])
        iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 / 24) //把相差的毫秒数转换为天数
        if (iDays > 90) {
            alert("查询时间范围超过90天,请重新选择!");
            return false;
        }
    }

<input id="inputOrderTimeStart" name="inputOrderTimeStart" runat="server" type="text" class="input80px" onfocus="WdatePicker({isShowClear:true,readOnly:true})"/>
                            至
                            <input id="inputOrderTimeEnd" name="inputOrderTimeEnd" runat="server" type="text" class="input80px" onfocus="WdatePicker({isShowClear:true,readOnly:true})"/>

<asp:Button ID="btnSearch" class="button_2 mgLeft0" runat="server" Text="查询" 
                                onclick="btnSearch_Click"  OnClientClick="return checkTime();"/>