CSS - adding a background to the Register button

Hi, Im using the upfront theme luke and Sarah for this website - http://tinyurl.com/h9u97fk
i added a widget for the login. however the register button is different to the login one.

can the same green button be applied please ? screenshot - http://take.ms/JZXAp

Support Access is open

Please dont post any brand related information/ screenshots or domain links as i have had issues with google caching this information and linking it to their google searches of my site ... very bad for brand... please use temporary image upload / tiny url / pastebin etc to mask this information.

Thanks
Tom