title: Jasper report : error with IF expression
body: <p>I am trying to append "%" to a textfield conditionally, but I am getting this error : </p>
  
  <ol>
  <li><p>The method IF(boolean, String, String) is undefined for the type </p>
  
  <p>SuiviExercice_1441008823562_230431
                  value = IF(((java.lang.String)field_libelle.getValue()).equals(""),String.valueOf(((java.lang.Double)field_octoberData.getValue()))+"%",String.valueOf(((java.lang.Double)field_octoberData.getValue())));
  &lt;></p></li>
  </ol>
  
  <p>Does anyone know why?</p>