[squid-users] Access denied - ACL problem

I am new to squid so please bear with me.
I have an internal server that runs a helpdesk application and should
allow users to access it using the computer name as the url on port 81.
I have added a PTR record in our internal DNS server to point
"servername" to the correct ip address.

http://servername:81

However, squid is displaying the following error.
+++++++++++++++++++++++++++++++++
ERROR
The requested URL could not be retrieved

While trying to retrieve the URL: http://servername:81/dashboard

The following error was encountered:

    * Access Denied.

      Access control configuration prevents your request from being
allowed at this time. Please contact your service provider if you feel
this is incorrect.

Your cache administrator is webmaster.
Generated Wed, 29 Aug 2007 16:40:50 GMT by sentinal (squid/2.5.STABLE12)

+++++++++++++++++++++++++++++++++

I can access this if I disable my proxy settings in the browser.
Can anyone tell me how to correct this.

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Received on Wed Aug 29 2007 - 10:48:11 MDT