can´t register more than one FK per table, why?

[João Galli]

HI,

well, I have a table that has 4 FKs
but I can´t link it to more than 1 table...

this is my sql:
ALTER TABLE `topassist`.`ordem_servico` ADD CONSTRAINT `FK_ordem_servico_pessoa` FOREIGN KEY `FK_ordem_servico_pessoa` (`pessoa_fk`)
REFERENCES `pessoa` (`id`)
ON DELETE RESTRICT
ON UPDATE RESTRICT,
ADD CONSTRAINT `FK_ordem_servico_tecnico` FOREIGN KEY `FK_ordem_servico_tecnico` (`tecnico_fk`)
REFERENCES `tecnico` (`id`)
ON DELETE RESTRICT
ON UPDATE RESTRICT;


CAN IT BE DONE?