Disclosed is a system and method for treating headaches. Moisture may be prevented from penetrating into the display device. The system employs constraint rules on tree ordering to reduce the computational complexity in arriving at optimized XML DTD schema. The first layer is compressible such that the second and third layers of material may be brought into contact with each other in the aperture of the first layer to complete an electrical connection between the second and third layers upon application of a compression force.