How to secure login area better?

I made my first "login area" control panel and set it up to allow certain people to view only what they are allowed, but about half way through the coding i realized that i have a BIG security issue. I was using a url variable to go from page to page, for example:

<a href="../user/user_list.cfm?Person=#qLogin.UserID#">User List</a>

The application works fine, but when I changed the number of the "person" in the URL from 2 to lets say 10 it would show person 10s information. I have been looking around for a solution, but haven't really found anything that i found useful. Here is the code i use to login to the control panel. So I need to make sure only that certain person is on the appropriate page and that they won't be able to change the person number at all.

( Application.cfc )

<cfcomponent>

    <!--- Any variables set here can be used by all our pages --->

           <cfset this.name="MyWebsite">

           <cfset this.clientmanagement="false">

           <cfset this.sessionmanagement="true">

           <cfset this.sessiontimeout=#CreateTimeSpan(0,0,20,0)#>

           <cfset this.loginstorage="Session">

           <cfset this.setClientCookies="true">

    <!---cferror type="Exception" template="errormessage.cfm"

           mailto="memmar@telus.net"--->

  <cffunction name="onRequestStart">

    <cfset APPLICATION.dataSource = "myDB">

    <cflogin>

      <cfif IsDefined("FORM.Login_btn")>

        <cfquery name="qLogin" datasource="#APPLICATION.dataSource#">

        SELECT UserEmail, UserPassword, UserRoleID, UserID

        FROM UsersAccess

        WHERE UserEmail = <cfqueryparam value="#cflogin.Name#" cfsqltype="cf_sql_varchar">

        AND UserPassword = <cfqueryparam value="#cflogin.Password#" cfsqltype="cf_sql_varchar">

        </cfquery>

        <cfif cflogin.name IS "#qLogin.UserEmail#" AND cflogin.password IS "#qLogin.UserPassword#">

          <cfloginuser name="#cflogin.name#"

                       password="#cflogin.password#"

                       roles="#qLogin.UserRoleID#">

        <cfelse>

        <!--- Redirects if the login information is incorrect --->

          <cflocation url="../signup/index.cfm?LoginError" addtoken="no">

            <cfabort />   

        </cfif>

      <cfelse>

        <cflocation url="../index.cfm" addtoken="no">

          <cfabort />

      </cfif>

    </cflogin>

  </cffunction>

</cfcomponent>