Javascript 验证日期范围的js

任何人都可以帮助我…如何验证此问题的javascript日期：

用户选择开始日期，结束日期将选择从开始日期起超过90天。如果结束日期低于90天，用户可以发送表单

from date code :
<input name="fromDate" type="text" id="fromDate" size="10" maxlength="10" onChange="">
<a href="#" name="anchorFrmDate" id="anchorFrmDate" onClick="calFrmDate.select(document.forms[0].fromDate,anchorFrmDate,'dd/MM/yyyy'); return false;">DATE</a>

to date code:
<input name="Todate" type="text" id="Todate" size="10" maxlength="10" onChange="">
a href="#" onClick="calToDte.select(document.forms[0].Todate,'anchorToDte','dd/MM/yyyy'); return false;" name="'anchorToDte'" id="'anchorToDte'"><strong>DATE</strong></a>

我已经试过了，下面是我的代码。。。但是不要成功。。。我弄错了哪一部分

function checkDateRange(fromDate, Todate) { 
   // Parse the entries 
   var startDate = Date.parse(fromDate); 
   var endDate = Date.parse(Todate); 
   // Make sure they are valid 
    if (isNaN(startDate)) { 
      alert("The start date provided is not valid, please enter a valid date."); 
      return false; 
   } 
   if (isNaN(endDate)) { 
       alert("The end date provided is not valid, please enter a valid date."); 
       return false; 
   } 
   // Check the date range, 86400000 is the number of milliseconds in one day 
   var difference = (endDate - startDate) / (7776000000); 
   if (difference < 0) { 
       alert("The start date must come before the end date."); 
       return false; 
   } 
   if (difference <= 1) { 
       alert("The range must be at least seven days apart."); 
       return false; 
    } 
   return true; 
}

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这是一张草图：

var startDateText = ...
var NINETY_DAYS = 1000 * 3600 * 24 * 90;
var startDate = new Date(startDateText);
var maxEndDate = startDate.getTime() + NINETY_DAYS;
..
var endDateText = ...
var endDate = new Date(endDateText);
if (endDate.getTime() > maxEndDate) {
    Window.alert("Too late");
}

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杜普？答案在这里吗？我真的希望这是一个家庭作业。