CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS


As independent public accountants, we hereby consent to the incorporation of our
report  included  in  this  form  10-K,  into  the  Company's  previously  filed
Registration  Statements  on Forms S-3 and Forms  S-8 (File  Numbers  333-09917,
333-10117, 333-09911 and 333-09909).


                                                       ARTHUR ANDERSEN LLP


Phoenix, Arizona
 December 14, 1998.