lock out users after three failed login attempts

I used Dreamweavers login wizard to secure a directory in my application (using simple authentication). That all works fine but now I need to add the functionality where a user would be locked out (temporarily - using a session variable) after three failed login attempts. I've tried many ways but I can't figure it out. I've enabled session management in my application.cfm and set the sessiontimeout variable. Where do I put the code (and what code would that be) that counts the attempts and then freezes it after three failed attempts?

This is the code in the mm_wizard_authenticate.cfc file:

<cffunction name="simpleauth" access="private" output="false" returntype="struct" hint="Authenticate using a single username and password">
<cfargument name="sUserName" required="true" hint="The username that was setup in the Login Wizard.">
<cfargument name="sPassword" required="true" hint="The password that was setup in the Login Wizard.">
<cfargument name="uUserName" required="true" hint="The username passed in from the client.">
<cfargument name="uPassword" required="true" hint="The password passed in from the client.">
<cfset var retargs = StructNew()>

<cfif sUserName eq uUserName AND sPassword eq uPassword>
<cfset retargs.authenticated="YES">
<cfelse>
<cfset retargs.authenticated="NO">
</cfif>
<cfreturn retargs>
</cffunction>

I'm thinking I need to add something like this (below) somewhere but I don't know where.

<cflock scope="SESSION" timeout="3" type="EXCLUSIVE">
<cfif NOT IsDefined("request.login") or request.login neq 1>
<cflocation addtoken="No" url="mm_wizard_login.cfm">
</cfif>
</cflock>

Any help gratefully appreciated. Thanks!