Prints are backwards?

So when i built my Prusa I3 and got everything going printed a nice test cube. however i then printed a iphone case and the print was flipped!

so basiclly when i manually move it pronterface or repetier they go the correct directions however my prints are mirrored.

So what do i do?

Is the printer really moving in the right direction? Look at the Y axis. When you move the Y axis in a positive direction, the bed should move to the front, and obviously when you move in a negative direction, the bed should move to the back. Don't think of it in terms of where the bed is, think of it in terms of where the print head is in relation to the bed. When the bed moves to the back (negative) the print head "moves" to the front of the bed.

This is a common mistake. You need to invert the direction of the Y axis - and your Y minimum end stop should be in the back of the printer.

looking at the printer as a graph the printer moves Positive and negative when i tell it to but prints backwards. i also thought the printer was in need to be flipped but it is going the correct directions

I had the same problem.
the x-axis was inverted.

Because the basic Marlin Config does not account for the end-stop placement of the prusa i3.

parts will be mirrored.
i fixed it by changing the endstop status to home on the Max and not on the min and inverting the directions.

so it homes at z0 y0 x200