A Bit of background.
I've decided to roll up a Warlock NPC as one of the final bosses for my campaign using the class from Complete Arcane since it fits in with some of the underlying themes and events of the campaign.
However, reading though the rules on the Warlock in Complete Arcane, I noticed that unlike other Arcane spellcasters, the Warlock doesn't seem to have a limitation on the number of times they can use their Eldritch Blast and/or Invocations per day, but neither does it say that their use is unlimited. Compared to other spellcasting characters, it does seem to imply unlimited use.
I've had a bit of a search around, but I cannot find anything concrete regarding the official Complete Arcane class, only for Homebrew.
Is there a use limit on the number of times a Warlock can use his/her Eldritch Blast/Invocations per day, or is their use unlimited?