How do you create the xml-string?

>I have created a small vfp-com dll that returns data as an xml-string. This works fine. However, if I return the string on a webpage I get the following message:
>Error: An invalid character was found in text content (in a dialog)
>
>When the string is shown in the browser you see the following:
>The XML page cannot be displayed
>Cannot view XML input using XSL style sheet. Please correct the error and then click the Refresh button, or try again later.
>
>Taking a close look into the string itself it is refering to the µ (greek-micro) character.
>
>I could remove this character but are the any more such characters that will give this problem. Is it possible to replace this character with an xml-allowed variant. Why can VFP generate this xml if it is not what Internet Explorer likes to have.
>
>Thanks in advance,
>
>Ron