function LoadMonth(mo, subc, classname) {
 if (mo != 1 && mo != -1) return; 
 c_month += mo;
 if (c_month > 12)
 {
  c_month = 1;
  c_year++;
 }
 if (c_month < 1)
 {
  c_month = 12;
  c_year--;
 }

 document.getElementById('current_month').innerHTML = c_MonthNames[c_month-1] + ' ' + c_year;
 document.getElementById('calentry').innerHTML = '<img src="'+calprogimg+'" />';
 Ext.Ajax.request({url : langpref + ajax_script.ajax_newscal + (subc ? subc + '/' : ''),
                   params : { y: c_year, m: c_month, cla: classname},
                   method: 'POST',
                   success: function ( result, request ) {
                              document.getElementById('calentry').innerHTML = result.responseText;
                            },
                   failure: function ( result, request) {
                              alert('Произошла ошибка');
                           }
                  });
 }