var mon=new Array(12);
        mon[0]="Jan";
        mon[1]="Feb";
        mon[2]="Mar";
        mon[3]="Apr";
        mon[4]="May";
        mon[5]="Jun";
        mon[6]="Jul";
        mon[7]="Aug";
        mon[8]="Sep";
        mon[9]="Oct";
        
        mon[10]="Nov";
        mon[11]="Dec";
    function checkDate(sender,args)
    {
        var now=new Date();
        var today = new Date(now.getYear(), now.getMonth(), now.getDate()); 
        if (sender._selectedDate < today) 
        {
           alert("You cannot select check-in date earlier than today!");
           sender._selectedDate = new Date(); 
                // set the date back to the current date
            sender._textbox.set_Value(sender._selectedDate.format(sender._format))
        }
        else
        {
            var valid=new Date(sender._selectedDate);
            var d=new Date(valid.setDate(valid.getDate()+1));
            if(document.getElementById("ctl00_ContentPlaceHolder1_txtCheckOut")!=null)
                document.getElementById("ctl00_ContentPlaceHolder1_txtCheckOut").value=d.getDate()+"-"+mon[d.getMonth()]+"-"+d.getFullYear();
        }
   }