Directed by Barry Levinson. Starring Jack Black and Ben Stiller. Rated PG.

Envy is a comedy about a middle-class dreamer named Nick (School of Rock's Jack Black) who invents a spray formula that makes dog poop evaporate into thin air. Thanks to the miracle of Va-Poo-Rize, Nick's sudden wealth gives new meaning to the phrase stinking rich. Our scatological Houdini tears down his modest suburban bungalow and builds a tasteless palace in its place. As the newly crowned king of infomercials, he keeps a horse as a house pet and tools around in a urine-coloured Lamborghini. Suddenly, his kid has a back-yard archery set that rivals the Olympics and his wife is dripping with so many jewels that she starts to resemble a talking chandelier.

All this conspicuous consumption is a big problem for Nick's neighbour Tim (Ben Stiller). Before Nick hit it big, the two car-pooling drudges worked at the same plant making sandpaper. As Nick's best friend, the ever-practical Tim was offered a chance to invest in Va-Poo-Rize. Tim passed, and after Nick's invention takes off he's consumed with jealousy. The comedy is supposed to come out of Tim's reluctant dance with the green-eyed monster.

The fact that Envy is directed by Barry Levinson--the man who gave us such memorable films as Diner and Good Morning Vietnam--holds out hope for wringing a few laughs from a very thin premise. Unfortunately, the Steve Adams script is devoid of anything resembling humour or satire. The screenplay--which features any number of lame sight gags and pointless riffs--can't even work up enough energy to be endearingly crude or stupid.

The cast doesn't help much. In School of Rock, Black showed signs of combining the well-rounded appeal of John Candy with the hip insolence of an early Bill Murray. Here, his performance is so subdued that it borders on lazy. He should take a good look at costar Stiller, who was the hottest comic property around after 1998's There's Something About Mary. Half a dozen years later, Stiller seems content to churn out the same hapless dork over and over. The trouble is, it gets less funny each time.

As for the supporting cast, Christopher Walken dons a hippie wig and does his best to provoke a few smiles as an obliging con man. Unfortunately, not even Walken's manic grace can pump life into this one. It would be nice to wrap things up metaphorically by likening Envy to a steaming pile of dog droppings, but the whole thing is so blandly inoffensive it doesn't even earn the right to be called crap.