Truclient Ajax: Can we Interupt the NTLM authentication on Firefox ?

I need to Do a performance testing on an application which uses NTLM on Fire fox. There is no way in the application, users ca key-in the login userid and password. So now it is always taking my Network logon to use NTLM.

but is there a way i can use some test logins through NTLM login? 

I am not seeing an option to add a web_set_user method, because the script is read-only mode. 

Thanks 

ThomasCPS

I am using VuGenVersion 11.50, Firefox is the latest version.