Contact definition-RADIOSS

Hi,

I am using Hypermesh and Radioss to simulate the deformation of a sandwich panel. I have to define the contacts between ttwo panels but I am not able to do it. The contacts defined by me using Interfaces(csurfs) option is not being read during the simulation due t which the topmost panel flies off.... Only the top panel deforms... Can Someone please help me with this? Its urgent... and thanx for your replies...