& btpartweight()
 
  Syntax: btpartweight (<partname>)
 
  This function returns the weight of <partname>.
 
  Error Messages:
 
  * If <partname> is not valid the function returns #-1 INVALID PART 
    NAME 
 
  Example:
  Given that XXL_ENGINE is a valid part and weighs 1
 
  > think btgetweight(xxl_engine)
  1.000