code: function chain_script_executed(script_obj,chain_group) {
  				if (chain_opts[_Debug]) log_msg("script execution finished: "+script_obj.real_src);
  				script_obj.ready = script_obj.finished = true;
  				script_obj.exec_trigger = null;
  				// check if chain group is all finished
  				for (var i=0; i<chain_group.scripts.length; i++) {
  					if (!chain_group.scripts[i].finished) return;
  				}
  				// chain_group is all finished if we get this far
  				chain_group.finished = true;
  				advance_exec_cursor();
  			}
docs: called when a script has finished executing