Our website and system uses a seamless function for flight planning. This is called sim Brief. Firstly you will need a FREE account register HERE

Thats it. Now ensure pop ups are enabled for ALVA site.
Book your flight and look in the home page to see your booked flights. The flight that you have booked will have a green BR at the side. Click this and a little window will open up enter your SimBrief registration details in there. Wait approx 10 seconds and the ALVA page will be populated with all info needed for that flight. There is also a Flight plan download to install directly to your FMC.