Catching an error message

I'm using Coldfusion Fusebox 3 and I would like to know how I can keep my app from throwing an error message if someone thoughtlessly removes the Circuit and fuseaction from the URL.
For example, if the original URL is: 

http://www.noname/Intranet/index.cfm?fuseaction=Bulletins.main
...and someone removes the circuit information so it reads like the following: http://www.noname/Intranet/index.cfm?fuseaction=
...the app throws an error message. Can I code against something like this happening?

Here is my fbx_Settings.cfm file as it exists right now. Thank you.

<!--- In case no fuseaction was given, I'll set up one to use by default. --->
<cfparam name="attributes.fuseaction" default="Login.showLoginForm">

<!--- useful constants --->
<cfparam name="request.self" default="index.cfm">

<!--- should fusebox silently suppress its own error messages? default is FALSE --->
<cfset fusebox.suppresserrors = false>

</code>