RAMPS 1.4 with LCD??

Hi all,
Ive nearly completed my first prusa mendel, im using RAMPS 1.4 with marlin firmware and have the LCD hooked up to the ramps board but cant seem to get the LCD to work, the RAMPS board definitely works as i can move the motors etc but the screen lights up and displays a row of blocks then a blank row then another row of blocks and another blank row, im guessing its firmware related, anyone know how to get it working?

Did you configure the firmware to work with the brand of LCD you are using?
There are several options towards the end of configuration.h file.

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