A Berkshire man has been jailed for posting abusive messages online about a schoolgirl after she committed suicide.Sean Duffy, 25, of Reading, was handed an 18-week sentence for posts on social networking sites about Worcester teenager Natasha MacBryde.He previously pleaded guilty at Reading Magistrates' Court to sending indecent or offensive communications.Police said Duffy also posted abuse about dead teenagers in Northumberland, Gloucestershire and Staffordshire.Posted videoDuffy admitted two counts of sending a communication of an indecent or offensive nature.The charges related to Facebook and YouTube posts about Miss MacBryde, 15, who Duffy had never met.She had thrown herself under a train in February after being bullied.Duffy subsequently posted messages on a remembrance page set up by Miss MacBryde's friends.