Hey Guys, 
I have implemented an AJAX Toolkit CalendarExtender.  I have a method 'CheckDate' in javascript (followed a tut!) that checks to see if the user selected a date > DateTime.Now().
Well, I have a few other things to check but not sure how to do them in javascript, so I'm hoping someone here can help me.  I mean, i can somewhat convert it but it'll be too mangled, I'd rather learn the right way.  I'm attaching the code and any help will be appreciated.
 
1            protected string CheckDateErrors(string dateGiven)
2            {
3                // let's make sure that the date entered by user
4                // does not exceed the present date or goes back
5                // over a year.
6                // we need to try parse! 
7                DateTime userDate = DateTime.Parse(dateGiven);
8                //DateTime userDate;
9    
10               int userYear = userDate.Year;
11               int userMonth = userDate.Month;
12               int userDay = userDate.Day;
13   
14               // not valid! user entered future date, can't allow this to happen
15               if (userDate.CompareTo(DateTime.Now) > 0)
16               {
17                   //this.tbBeginDate.ForeColor = Color.Red;
18                   //this.tbBeginDate.BorderColor = Color.Red;
19                   return "* Cannot Enter Future Dates;";
20               }
21               // date cannot be more than one year old.
22               else if (userDate.CompareTo(DateTime.Now) <= 0)
23               {
24                   int difference = DateTime.Today.Year - userYear;
25   
26                   // going too far back; now allowed.
27                   if (userYear < (DateTime.Today.Year - 1))
28                   {
29                       return "* Cannot Enter Past One Year: Compared Years;";
30                   }
31                   else if ((difference == 1) &&
32                       (userMonth < DateTime.Today.Month))
33                   {                
34                       return "* Cannot Enter Past One Year: Compared Months;";
35                   }
36                   else if ((difference == 1) &&
37                        (userMonth >= DateTime.Today.Month) &&
38                        (userDay < DateTime.Today.Day))
39                   {
40                       return "* Cannot Enter Past One Year: Compared Days";
41                   }
42   
43                   return "none";
44   
45               }
46   
47               return "none";
48   
49           }
  
 
Carpe Diem!

Hi 
In order to validate date in javascript , you need to create a two date object's in javascript which will represent the current date and the date which you have selected by using Calander control . 
Now following are the ways with which you can create a date object in javascript:-
Date() - Use the current date and time to create an instance of the object date. 
Date(dateString) - Use the date specified by the string to create the instance of the date object. String format is "month day, year hours:minutes:seconds". 
Date(year, month, day) - Create an instance of date with the specified values. Year is 0 to 99. 
Date(year, month, day, hours, minutes, seconds) - Create an instance of date with the specified values. 
I have not modified your code but I am just giving few lines from my code which you can use to validate the date . Remember you will have to put some logic from your side in the code which I have mentioned below :-
// Function to validate dates before processing
function ValidateDate()
{
    var returnValue = 0;
    
    // Todays date
    var currentDate = new Date();
    
    // Array decleration
    var arrayMonths = new Array('Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
    
    var tempdate = new Date();
    
    // Temporary startdate object
    var tempStartDate = <Entered Date or date selected from calander control>; // I am using the following format dd-MMM-YYYY , if you are using different  format then you need to modify the next three lines to get extarct year , day , month 
    var startYear = tempStartDate.substring(tempStartDate.lastIndexOf('-')+1); // get the year 
    var startDay =  tempStartDate.substring(0 , tempStartDate.indexOf('-'));   // get the day
    var startMonth =  tempStartDate.substring(tempStartDate.indexOf('-') + 1 , tempStartDate.lastIndexOf('-'));  // get the month
    
    // Start date
    var startDate = new Date(startYear , arrayMonths.indexOf(startMonth), startDay); // Create an instance of date object in a format which javascript understands( javascript representaion of selected date)
    // After this you have to implement the logic of date validation 
    // For this you can make use of various javascript method like getYear() , getDay() etc on date object to extract relevant information 
    // Also once you have instantiated date in the form of javascript object you can use arithmatic operators like < , > , >= , <= , === , !== etc 
}
And while you are validating your selected date following link will be of great help to you :- http://www.comptechdoc.org/independent/web/cgi/javamanual/javadate.html
Also there can be various ways by which you can validate date , the above approach may seems more complex and cumbersome but I learned a lot from the above approach . If you can get some more efficient method please provide the same in current thread .
Regards
Pawan Mishra
“The greatest compliment that was ever paid to me was when one asked me what I thought, and attended to my answer.” - Henry David Thoreau 

Pawan,
 thanks a LOT for the help.  I've been using your help as well as the link to convert my method to a javascript function.  I am stuck on one part though. 
 
 
1    else if(sender._selectedDate <= currentDate)
2                {
3                   //var userDate = (Date)(sender._selectedDate);
4                    var yearDay = usersender._selectedDate.getDate();
5                    var userMonth = sender._selectedDate.getMonth();
6                    var userYear = sender._selectedDate.getYear();
7                    
8                    int difference = currentYear -  userYear;
9                
10                   // going too far back; now allowed.
11                   if (userYear < (currentYear - 1))
12                   {
13                       alert("Error: No Dates Past A Year Allowed");
14                   }

 The problem is located in lines 3-6.  I need to extract the month, year, and date from sender._selectedDate.  I'm not sure how to do this part in JS.  Can anyone help me, please?  Thanks.
Carpe Diem!

Hi 
getDate() , getMonth() etc kind of functions will work only with date whose format is actually compatible with javascript date format . For eg in your javascript function give :-
var date = new Date();
alert(date); --> result will be something like this " Tue Dec 9 smthn smthn " . 
Since in my application the date format of calander extender control which i was using was dd-MMM-YYYY so i had to maually write the code to extract the specific information which is day , month and year and then pass these details into the constructor of date class of javascript . 
If you can tell me which format you are using in you application I can then help you in getting through your problem.
Regards
Pawan Mishra
“The greatest compliment that was ever paid to me was when one asked me what I thought, and attended to my answer.” - Henry David Thoreau 

Hi Pawan,
Thanks a lot for your help.  You've been extremely helpful.  My date format is MM/dd/yyyy.  Looking at your example code, which somehow I missed!, I believe I know what to do.  I will update this post in a little bit.  You rock!
Carpe Diem!

I'm still having issues and have a few questions.  I will first paste the code: 
 
1    var userDate = sender._selectedDate;
2    alert("userDate: " + userDate);
3                    
4    var hi = userDate.substring(1, 3);
5    alert("hi!");
6    var userYear = userDate.substring(userDate.lastIndexOf('/')+1); 
7    alert("userYear/lastIndexOf: " + userDate.substring(userDate.lastIndexOf('/')+1));
8    
9    var userMonth =  userDate.substring(0 , userDate.indexOf('/'));  
10   var userDay =  userDate.substring(userDate.indexOf('/') + 1 , userDate.lastIndexOf('/')); 
11   alert("MM/dd/yyyy: " + userMonth + "/" + userDay + "/" + userYear);
Ok, first regarding what format I'm  using.  This is the exact code in designer:
 
a    <cc1:CalendarExtender ID="CalendarExtender2" runat="server" TargetControlID="tbEndDate"
b                               PopupButtonID="Image2" OnClientDateSelectionChanged="checkDate" Format="MM/dd/yyyy" />

 Lines 1 & 2 execute.  The alert box shows me this format "Thu Dec 4 00:00:00 EST 2008".  Should it not show me 12/04/2008..?   Have I confused something here?  Lines 4 & 5 were added to see wth was going on since I kept getting the error in IE "Object does not support this method or property".  Since line 6 uses substring and indexOf, I had to determine what method isn't working properly.  Turns out line 4 is where the code craps out.
 Pawan or anyone else, can anyone help me out here?  I am using IE 7 (not by choice, but this is what 99% of our users use here).
Carpe Diem!

Hi
You can check the following code , I have written to modify to validate of format MM/dd/YYYY :-

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="TextChanged.aspx.cs" Inherits="Admin_TextChanged" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > 
<head runat="server">

<title>Temp1</title>

<script language="javascript" type="text/javascript">

// Function to validate dates before processing
function ValidateDate() 
{var returnValue = 0; 
 
// Todays date
var currentDate = new Date(); 
 
// Temporary startdate object
var tempStartDate = $get('txtCal').value; 
var toYear = tempStartDate.substring(tempStartDate.lastIndexOf('/')+1);
var toMonth = tempStartDate.substring(0 , tempStartDate.indexOf('/')); var toDay = tempStartDate.substring(tempStartDate.indexOf('/') + 1 , tempStartDate.lastIndexOf('/')); 
// Start date
var startDate = new Date(toYear , toMonth - 1 , toDay); 
 if(startDate > currentDate) 
{
alert(" Start date cannot be greater than todays date "); 
}
// Here you can carry on your validation I have just validated one scenario where selected date should not be greated than todays date

}</script> </head> 
<body>

<form id="form1" runat="server">

<div>

<ajax:ScriptManager ID="script1" runat="server" EnablePartialRendering="true"></ajax:ScriptManager>

<asp:Button runat="server" ID="btnClick" Text="Button" OnClientClick="ValidateDate()" />

<asp:TextBox runat="server" ID="txtCal"></asp:TextBox>

<ajaxToolkit:CalendarExtender BehaviorID="Cal1" ID="Cal" TargetControlID="txtCal" runat="server" Format="MM/dd/yyyy"></ajaxToolkit:CalendarExtender>

</div>
</form> </body> 
</html>
 
Let me know if you need some more help :-) ....
Regards
Pawan Mishra
“The greatest compliment that was ever paid to me was when one asked me what I thought, and attended to my answer.” - Henry David Thoreau 

Pawan,
 var tempStartDate = $get('txtCal').value; 
does the trick!  Great.  Last question:

sender._textbox.set_Value(sender._selectedDate.format(sender._format))
The above line.... what if I want to leave the textbox blank?  I tried '' and ' ', but got an error.  Got ideas? 
 
Carpe Diem!