[OpenLayers-Users] registering featuremodified

[Adorian Ardelean]

Hi,

I am trying to register a "featuremodified" event to a vector layers 
containing a feature built from a GeoJSON file.

For registering event, I have used both methods below:

trails.events.register('featuremodified', '',serialize);       
or  
trails.events.on({featuremodified: 
function(feature){alert(feature.id)}});        


serialize = function (feature) 
{
    alert(feature.id);
}

In both cases I receive an "undefined" in message box.

Could somebody guide me on how this event should be registered so that I 
can get access to feature data?

Best regards,
Adorian