Want an easy way to get tickets to “The Book of Mormon?” The touring smash hit, all but sold out for its three-week run at the Opera House, has added a show Thursday at 1 p.m. to make up for Friday’s canceled performance. And last check, there were plenty of Thursday matinee seats listed on Ticketmaster. Friday’s show, of course, was canceled amid the Boston-area lockdown while police and federal agents searched for Marathon bombing suspect Dzhokhar Tsarnaev. Folks holding tickets for Friday’s show were given first crack at tickets to Thursday’s show. But not everyone is happy about the arrangement. Diane Marsili, who had tickets to see the show Friday night, said she won’t be able to see the Thursday performance because she’s working. “First, let me say that our disappointment over a canceled show in no way compares to the pain, suffering, and loss caused by this tragedy,” Marsili wrote via e-mail. “That said, I do not think this has been handled well at all.” Marsili said she doesn’t understand why Broadway in Boston couldn’t have added a Monday evening performance and honored April 19 tickets. Here’s one simple reason: The touring show closes its Boston run Sunday and heads to Toronto for a Tuesday night performance.