How to convert special characters to normal characters?

Question

I am trying to convert characters like:

ë, ä, ï, ö, etc.

To normal characters like:

e, a, i, o, etc.

What

Answer 1

i like stewies' answer, but for completeness this works for me.

preg_replace("/&([a-z])[a-z]+;/i", "$1", htmlentities($foo));