Thanks for the fast reply.
So when I used the code above I didn't get the error message, but the 'upload' button still doesn't work.
However, I'd tried something else: I put the above code in a blank .php file and ran it on my host server and it appeared to work as it should. But, when I put the standard code in a blank file and ran it, it worked but I still got the error message displaying.
I hope that makes sense..
Here's the phpinfo output on my host http://www.freebizwebsite.com.au/phpinfo.php