The steps are list below:
1. create a capx.
+System: Start of layout
[li]Ajax request "readme.txt" (tag "read")[/li]
[/ul]+ Ajax: on "read" complete
[li]Set text to AJAX.LastData
2. use run layout.
of course, the ajax will not be completed.
3. search "preview.html" from my c:for example, I got the "preview.html" in path
4. open this folder. There are many js files like AJAX_plugin.js, Text_plugin... etc.
5. put "readme.txt" into this folder.
6. open "preview.html"(in this folder) on browser.
Now, the "readme.txt" file is in the same folder within "preview.html". And the Ajax is completed.
Since this folder is created by C2 editor, and editor copy all necessary js files into it.
Maybe editor can put "readme.txt" into this folder. So that "readme.txt" can be found in this case.