Locutionary act: This term refers to the surface meaning of an utterance. Example: my saying to you "Dont go into the water" (a locutionary act with distinct phonetic, syntactic and semantic features) counts as warning you not to go into the water (an illocutionary act), and if you heed my warning I have thereby succeeded in persuading you not to go into the water (a perlocutionary act).
Illocutionary act: In uttering the locution "Is there any salt?" at the dinner table, one may thereby perform the illocutionary act of requesting salt, as well as the distinct locutionary act of uttering the interrogatory sentence about the presence of salt, and the further perlocutionary act of causing somebody to hand one the salt.
Perlocutionary act: Consider the utterance "By the way, I have a CD of Debussy; would you like to borrow it?“ Its illocutionary function is an offer, while its intended perlocutionary effect might be to impress the listener, or to show a friendly attitude, or to encourage an interest in a particular type of music.Taken from: http://en.wikipedia.org/wiki/Speech_act