On Wed, 5 Oct 2005 22:53:01 +0200, "Maarten" <rijt@dse.nl> wrote:

>I've got the following problem.
>
>In a text field people can give their last name.
>With this input an pdf file is created.
>This works fine until a user has an space or an special character in their
>lastname like '.
>
>I would like to do the following:
>if a lastname contains other characters than normal letters replace them
>with an underscore.
>How can I do that?
>
>Maarten

You need a regular expression.

preg_replace ("/[^a-zA-Z]/e", "_", $string);