This function returns the number of fields in a level.
In this example, we retrieve the number of fields in the 2nd point defined previously:
Result = EOS_PT_NFIELDS( pointID, level [, LENGTH=bytes] )
Returns number of fields if successful and FAIL (–1) otherwise.
Point id (long) returned by EOS_PT_CREATE or EOS_PT_ATTACH.
Level number (0-based long).
Size (long) in bytes of fieldlist for level.