function main_alert(message,type,identify){
  $('#main_alert').append('<div id="main_alert_'+identify+'">'+message+'</div>');
  $('#main_alert_'+identify).addClass(type);
  $('#main_alert_'+identify).delay(1500).slideDown('slow');
  $('#main_alert_'+identify).delay(5000).slideUp('slow',function(){
    $('#main_alert_'+identify).remove();
  });
}