A student called his mom from college and asked her for some money. His mother said, "Sure, sweetie. I'll send you some money. You also left your economics book here when you visited two weeks ago. Do you want me to send that up too?"
"Uh, oh yeah, okay," he said.
So his mom wrapped the book along with the checks up in a package and sent them at the post office. When she got back, her husband asked, "How much did you give him this time?"
"I wrote two checks, one for $20, and the other for $1,000."
"Are you crazy?" he asked.
"Don't worry," she said. "I taped the $20 check to the cover of his book, but I put the $1,000 one somewhere between the pages in chapter 15!"