Grandma and Grandpa were visiting their grandkids overnight. When Grandpa found a bottle of Viagra in his grandson's medicine cabinet, he asked about using one of the pills. The grandson said, "I don't think you should take one. They're very strong and very expensive." "How much?" asked Grandpa. "$20.00 a pill," he replied. "I don't care," said Grandpa, "I'd still like to try one, and before we leave in the morning, I'll put the money under the pillow. " Later the next morning, the grandson found $120 under his pillow. He called Grandpa and said, "I told you each pill was $20, not $120. "I know," said Grandpa. "The hundred is from Grandma!"