Prueba con algo asi y nos comentas :)
    
Código SQL:
Ver original- CREATE PROCEDURE sp_info_dorsal @nomeq VARCHAR(20), @director VARCHAR(50) 
- AS 
- IF @nomeq IS NULL OR @director IS NULL 
- BEGIN 
- RAISERROR ('NULL values are not allowed', 14, 1) 
- RETURN 
- END 
- SELECT * FROM dorsal WHERE nomeq=@nomeq AND director=@director