“American Idol” is taking voting online. Viewers will be able to cast votes through Facebook, along with the previous options of phone and text message, when the contest shifts from judges’ to audience’s choice next Tuesday. It’s the first time Internet voting will be part of the Fox series, which is in its 10th season. Toll-free phone and AT&T text-message voting, at standard rates, will continue. Online participation will be limited to viewers in the United States, Puerto Rico and the U.S. Virgin Islands who have a Facebook account, Fox said. Each person can cast up to 50 online votes. After selection of the 24 semifinalists this week, the 12 male contestants will take the stage Tuesday, followed by the top dozen female singers on Wednesday. The finalists will be announced next Thursday, March 3rd, with the size of the field as yet unannounced.