printed nothing but the code itself
in my output jsp page.
According to TLD or attribute directive in tag file, attribute value does not accept any expressions'
From jstl1.1 onwards it allows real time expressions. Did you download jstl1.0 ?
Before we started with your question everything was working well (with c:set en c:choose)
Where does your taglib directive in your jsp point to? Did you change that?