how detect when new map images are downloaded

[binyamintrachtman]

i need to cache the event when new map images are download while scrolling throw the map

how can i do this

[derekswingley1]

I don't really understand what you're saying...but every map layer has an onUpdate() event you might be interested in:  http://help.arcgis.com/en/webapi/javascript/arcgis/help/jsapi/layer.htm#onUpdate