The steps for UTF-8 support are described in the UTF-8 Setup page in the documentation:
- Change the PHP encoding. See the documentation for details on how your Home → Options → PHP page is meant to look like.
- Change the file encoding. From the Code view of your page, right-click anywhere in the code and select File Format → UTF8.
- Change the (M)Page encoding. From the Design view, use the Object Inspector to set the Encoding property to Unicode | utf-8.
If your system uses a Turkish locale, it should work. On Windows 7: Start → Control Panel → Change Display Language → Administrative (tab) → Language for non-Unicode programs
If with everything, the template preview still shows the worng characters, make sure you have the following code in your template, in the <head></head>:
<meta charset='utf-8'>