Unable to load tag handler class "org.eclipse.birt.report.taglib.RequesterTag"

i included birt.tld in web-inf/lib/birt.tld
in one of the jsp page i added <birt:parameterPage> and <birt:paramDef> tags for the report parameters
when i click on for that jsp page it shows
org.apache.jasper.JasperException: /xxx.jsp(16,0) Unable to load tag handler class "org.eclipse.birt.report.taglib.RequesterTag" for tag "birt:parameterPage"

can anyone help for trying out this