$(function(){
    $('#StartDate, #EndDate').datepicker(
                {
                showOn: "both",
                beforeShow: customRange,
                buttonImage: './img/calendar.png',
                buttonImageOnly: true
                });
    });

function customRange(input) 
{ 
         if (input.id == "StartDate")
         {
            return {
                     
                     minDate: (input.id == "StartDate" ? new Date(2009, 12, 1) : null),
                     maxDate: (input.id == "StartDate" ? $("#EndDate").datepicker("getDate") : null)
                   }; 
         }
         else if (input.id == "EndDate")
         {
            return {
                     
                     minDate: (input.id == "EndDate" ? $("#StartDate").datepicker("getDate") : null), 
                     maxDate: (input.id == "StartDate" ? $("#EndDate").datepicker("getDate") : null)
                   }; 
         }                        

}