While many scriptwriters have been on their feet picketing recently, some budding Chicago-based writers have actually had a pen in hand. Recent graduates of iO Theater’s writing program have written speculative scripts of episodes of popular sitcoms including “How I Met Your Mother,” “30 Rock” and “The Office.” While reruns of those shows air on TV, the students’ scripts will be read aloud by improvisers and actors for the next five consecutive Tuesdays at the iO. “We create our own new story line and ideas. It’s a little like fan fiction,” says one graduate, Lisa Linke. Although the writers might put some creative spin on their episodes, they try to stay true to the characters’ personalities. “I’m not going to have a show where Dwight and Pam get together,” says Linke, whose episode of “The Office” includes the characters enduring a weight-loss challenge. “We push the envelope a little, but at the end of the show everything’s kind of back to the way it was,” she says.