select multiple layer and apply effect

Hi i am new to scripting my current  script can only process one layer, how can i select multiple layer and add single effect

plz help...this is my script :

var activeItem = app.project.activeItem;

var curLayer = activeItem.selectedLayers[0];

//identify

if (curLayer.matchName == "ADBE AV Layer"){

//add Effect

var slider = curLayer.Effects.addProperty("ADBE Fast Blur");

}

[Moved from the general AE forum to a more specific one - Mod]