Incompatible key type SET<Id> for MAP<Id,String>: save Error
i have a map 

      Map<id,String>	map1= new Map<id,String>();

I am assigning values into this map

      map1.put(aList[j].id,err.getMessage()); // err is the database.error and aList is a list of accounts.

i am trying to loop through all the map records and i get a error here
       Save error: Incompatible key type SET<Id> for MAP<Id,String>

      for(set<id> ids : map1.KeySet())
    	{
    		system.debug(map1.get(ids));// i get a error here  
        }

 Any ideas what could be causing this
Thanks

Incompatible key type SET<Id> for MAP<Id,String>: save Error
===

i have a map 

      Map<id,String>	map1= new Map<id,String>();

I am assigning values into this map

      map1.put(aList[j].id,err.getMessage()); // err is the database.error and aList is a list of accounts.

i am trying to loop through all the map records and i get a error here
       Save error: Incompatible key type SET<Id> for MAP<Id,String>

      for(set<id> ids : map1.KeySet())
    	{
    		system.debug(map1.get(ids));// i get a error here  
        }

 Any ideas what could be causing this
Thanks
