def get_param(param, param_file):
   """Return the parameter value (as a string) found in a simple parameter 
      file with <param> = <val> assignments.  None is returned if not found."""
   pfile = open(param_file)
   ret = None
   for line in pfile:
      if(line.find('=') > -1):
         tokens = line.partition('=')
         cur_param = tokens[0].strip()
         cur_val = tokens[2]
         if(cur_param == param):
            ret = cur_val
   pfile.close()
   return ret