Phantom door frame.

integer linknumber;
   default
{
    touch_start(integer num_detected)
    {
        linknumber = 1; // Set this as the link number of the prim you want phantom.
        llSetLinkPrimitiveParamsFast(linknumber, [
               PRIM_PHYSICS_SHAPE_TYPE,PRIM_PHYSICS_SHAPE_NONE]);
    }
}