Login script to map network drive not working

Hi,
So I have the below login script set for all users to map a network drive located on another network which the office has a VPN tunnel to:

@echo off

echo Please type your network user name

set /p username=


echo Please type your network password

set /p password=

Net use Z: \\Share\Shared$ /user:DOMAIN\%username% %password% /persistent:YES

The script works fine when run manually, but I just cant seem to see why it doesn't run on logon. When I pull gpresult it states it has applied successfully.

Thanks
Craig