c:if tag is not working for scope

c:if tag is not working for scope

I am using strtus 1.3. In that application I want to use a <c:if> tag:
<c:if test="${requestScope.regerr ne null}">
but when I am using jsp page give me a warning:
test does not support run time expression
and console I got an error
org.apache.jasper.JasperException: /Reg.jsp (line: 14, column: 0)
According to TLD or attribute directive in tag file, attribute test does
not accept any expressions
So how could I use with scope? In this I want to check whether in the
request Scope regerr is null or not?