The EIf file down loaded from MATLAB files under
Chapter 5 must be placed in your m-file list as an
ascii file without file extension. Otherwise, you
are going to get the error 'Cannot open Eif.mat'.

   A procedure to handle this file is as follows
(verified for Netscape):
 

 (1). From the McGraw-Hill download site, click on the 
      file EIf and it appears on your screen.
 
 (2). Select 'Save As'. In the dialog box, under File 
      Name: enter "EIf." leaving the extension beyond the 
      dot blank. Under Save as type:, select All Files(*.*).
 
 (3). Target your m-file directory and save.