Expand-Image without JavaScript (Technics)
For XHTML it should read
script type="text/javascript"> <* <![CDATA[ */ document.write(' <a href="#" onclick="ajax_preview(226); return false" title="Show preview"> <img src="templates/default/images/ajax_preview.png" alt="Show preview" width="11" height="11" /></a>') /* ]]> */ </script>
instead.
Isn't that the way for XHTML 1.1 only?
You also may omit either the 'width' or the 'height' statement of any image
Hm, OK, this would save a little bit of code. Anyway I'm not that much convinced of this practice.
A further improvement would be referring to either a script in the <head> or even an external script, which contains the 'document.write'-stuff. Assignment would just contain the thread's id as a variable.
That's a question of separating code from design (or in this case keeping design issues in the tepmplates): As the ajax preview is also part of the design the HTML structure should IMHO be marked out in the template file.