Dynamically generating PHP functions?

Hey, I have written a script that dynamically generates a form from a given database and table that would be suitable, as a generic data input device for any mysql table. My problem is that when I have tried to write the script for the forms action i.e.: ... mysql("database","INSERT INTO table Values ( '$field1', '$field2', '$field3', '$field4' )"); I cannot figure out how to generate the above function dynamically so that that it has the correct number of fields for the given database table, does anyone know how one would go about writing php functions dynamically then executing them? I suppose it is much the same as the way php dynamically generates html, but I need it to do it on itself, if this makes any sense. Any help would be much appreciated. Joseph