Flat Battery

[gazza1971]

Went to use the car Saturday the battery was flat jump leads it started no problem used it all day no problems .The wife went to open it last night the remote locking wouldn't work opened with key alarm went off only one door opened I came home from work its the same battery is flat even with jump leads on it does nothing .Going to replace the battery today will this be the cure guys seems like its got no power at all even with jump leads it would not turn over no remote unlock central locking aint working went to start it the factory alarm is going of the indicators flashing like its immobilised its a 2.0 16v coupe .