Little Johnny asked and received help from a librarian on how to use the card catalog. In a little while, he approached the librarian again, wanting to know how to spell "tequila".
"T-e-q-u-i-l-a," spelled the librarian, and Little Johnny thanked her and went back to his search.
A short time later he came to the desk, looking quite distraught.
"I just can't find it," he said. "What book are you looking for?" the librarian asked.
Replied Little Johnny, "Tequila (To kill a )Mockingbird."