function customRange(input) {
    var max_date = $('#start_date').datepicker('getDate'); 
    var min_date = $('#start_date').datepicker('getDate');
    
    max_date.setDate(max_date.getDate() + 30) ;
    min_date.setDate(min_date.getDate() + 1) ;
    
    var options =  {
        minDate: min_date,
        maxDate: max_date
    }
    
    return options;
}

$(function(){
   $("#start_date").datepicker({
    numberOfMonths: 2,
    minDate: 0,
    yearRange: "2009:2012",
    dateFormat: "yy-mm-dd",
    duration: 'fast',
    onSelect: function()
        {        
            $("#start_dateAnchor").html(
                change_sql_date($("#start_date").val(),'d M Y')
            );
            
            if($("#start_date").val() >= $("#end_date").val())
            {
                 var end_day = change_sql_date($("#start_date").val(),'d');
                 var end_month = change_sql_date($("#start_date").val(),'m');
                 var end_year = change_sql_date($("#start_date").val(),'Y');
                 
                 end_day++;
                 
                 var end_date_val =  end_year + "-" + end_month + "-" + end_day;
                 end_date_val = change_sql_date(end_date_val,'Y-m-d'); 
                 
                $("#end_date").val(end_date_val);
            } 
                
            $("#end_dateAnchor").html(
                change_sql_date($("#end_date").val(),'d M Y')
            );
            
            $("#start_date").datepicker( 'hide' , 'fast' );
        }
    });
    
    $("#end_date").datepicker({
        beforeShow: customRange,
        numberOfMonths: 2, 
        dateFormat: "yy-mm-dd",
        yearRange: "2009:2012",
        duration: 'fast',
        onSelect: function()
        {        
            $("#end_dateAnchor").html(
                change_sql_date($("#end_date").val(),'d M Y')
            );
            
            $("#end_date").datepicker( 'hide' , 'fast' );                                                 
        }
    });
    

});