I need help to set up Marlin correctly

Hello everyone.

This is the first 3D printer I'm building and I've done a quick set up of Marlin on Arduino IDE,

I just need a little help, nothing has blasted on fire at the first start (which is very good), I've encountered the following issue,

None of the steppers, after moving them via the "move axis" cmd, will go back, they only go forward.

I'm using a RAMPS 1.4 over an Arduino Mega2560.

is there any command I've forgot to define in Arduino?

thanks for the reply.

If the steppers will not return to there original positions then you may want to check the end-stop switches for correct wiring / configuration.

If you post your configuration.h file to a google drive for download we will take a look see.
More information about you 3D Printer will be required though so we can make a intelligent decision on what configuration settings are needed.