带有输出参数的存储过程

CREATE PROCEDURE aaa

@abc char(10),
@mycount int output
AS
select @mycount=count( *) from employees where pusercode=@abc
return
GO

如何提取参数
procedure TFrm_worker_info.Button1Click(Sender: TObject);
var outcount:integer;
begin

ADOStoredProc1.Parameters.ParamByName('@abc').value :='00001';
ADOStoredProc1.ExecProc；
showmessage(inttostr(ADOStoredProc1.Parameters.ParamByName('@mycount').value));