Suggest Treatment For Cold And Runny Nose In A Child

Hi Doctor My 3yr old son is suffering from severe cold.He is suffering from running nose and his nose gets block when he sleeps.i m giving him montair LC syryp 5ml bed time but no relief earlier i gave maxtra for 5 days but no relief .He has become so irritated because of cold.i m also giving him metspray once at bedtime.plz suggest how to get rid of his problem.please suggest as he frequently suffers from cold.