Electromagnets capability of repulsion.

I am wondering if anybody can inform me of how to use an electromagnet to repulse a small platform of Aluminium in the air to about 6 inches. NOTE: the platform is 65mm in radius and will have numerous amounts of neodymium magnets spread across the underside facing in same polarity to the electromagnet below. I'm still in confusion whether to place the electromagnet with poles facing vertically or horizontally (although the general theory is vertical). Any help in this matter would be greatly appreciated.