function showEvents(type){

                if(type == 'all')
                    $('.cal_event').show();
                else{
                    $('.cal_event').hide();
                    $('.class_' + type).show();
                }
            }

            function showDesc(class_name, event){
                $('#class_desc_container').show();
                $('#desc_' + class_name).show();
            }

            function hideDesc(){
                $('.class_description').hide();
                $('#class_desc_container').hide(); 
            }