Mysqli support - test or complain?

PHP List, Based on what seemed to be good advice to switch to using mysqli for interacting with a MySQL database, I built a content management system that uses mysqli for all it's calls. It works great on a lot of my servers. However, I just discovered that one web hosting service I use does not have mysqli enabled. I ran the phpinfo() command and they are running 5.2.5, but the configure command does not contain "--with-mysqli". I would like the scripts I've written to be somewhat portable, but I'm unsure of whether or not I should assume that mysqli is in use. I see it as being a situation of essentially two options. One is based on the assumption that mysqli is as likely not to be available as it is to be installed. In this case I should write my scripts to test whether it exists and then use either mysqli or straight mysql commands as appropriate. If this is the way to go, what do I do to test for the existence of mysqli from within a PHP script? The other is to assume that recent installs and upgrades of PHP > 5 should have mysqli because that's the currently preferred way of doing things, and therefore I should contact the web host and ask that they install it, or I find a different host. Which assumption should I be proceeding with? Thank you for any advice or assistance. -- Dave M G