SPRINGFIELD, Mo. - Wal-Mart Stores Inc., under a new barrage of criticism for how it treats its workers, is going on the offensive a week before the launch of a documentary that attacks the retail giant. The company alleges that director Robert Greenwald's movie "Wal-Mart: The High Cost of Low Prices" gets basic facts wrong. The world's biggest retailer and largest private employer in the United States, with 1.2 million domestic workers, is also touting a rival DVD release, "Why Wal-Mart Works: And Why That Drives Some People C-R-A-Z-Y". "I'm a bit surprised at the amount of money that they...