need help!

[hualiang]

yesterday I was trying to solve some printing problems related to matlab

I followed the instruction given in the below link:
http://www.mathworks.com/support/solutions/en/data/1-5DRO9Z/index.html

I opened 'http://localhost:631' and trying to add 'Printcap /etc/printcap' into CUPS configuration file, and it is not successful

Now my iMAC cannot print now, if I click the 'print&fax' in system preferences, the small cursor just keep rotating for ever...

can anyone tells me how to fix such problems?

thanks a lot!