PHP code samples using Informix functions?

I'm trying to use PHP with Ix Foundation 2000, and I have to admit that I can't figure out how to do certain basic things just from reading the PHP on-line manual. Is there a good Web-based source of code samples or a tutorial or something for the Informix functions? What I'd like to do, written in pseudo-4gl, is something like: let variable = "select * from table where field = ?" prepare s1 from variable declare q1 cursor using s1 while let value = something different open q1 using value end while PHP has ifx_prepare and ifx_do, but they don't seem to allow you to prepare a statement with placeholders for values to be inserted later, which is a good thing to do because the search optimizer then doesn't have to re-evaluate the statement every time it goes through a loop with a different value.