Pam

Hi I'm new to this forum. I have a astra elite turbo and today i went to start it and it wouldn't turn over, nothing. We called out the AA hoping it was maybe a flat battery, but after trying several times with jump leads they suspect its a problem with the key. Can anyone shed any light on this, we don't have a spare key to try. Sounds like it could be expensive. I just don't know what to do. Look forward to your comments. Regards Pam