"The Dark Knight" is Heading for Best Opening Ever...

According to Fandango, tickets for the upcoming "The Dark Knight" are selling out, even though the film is still three weeks away from being released in theaters. Lots of midnight screenings have sold out and many theaters are now adding 3am showings to meet the demand.

Joel Cohen, executive vice president at MovieTickets.com said that "The Dark Knight" is doing surprisingly well, since the first film in the series, "Batman Begins," never created such a craze.

"It's tracking much stronger than 'Spider-Man 3' at the same time in the sales cycle," he said. The third installment in the "Spider-Man" franchise went on to set the record for best opening weekend ever. This might be a hint of what we can expect from "Knight."

According to predictions, the film is likely to earn way more than $100 million during its first weekend. "Iron Man" sold $102.1 million worth of tickets, while "Indiana Jones and the Kingdom of the Crystal Skull" took in $100.1.

But in order to break "Spider-Man 3" numbers, "Dark Knight" has to bring in more than $151 million.

"The Dark Knight" is set to appear in theaters on July 18th with early showings starting at midnight the night before.