What can be the reason for attribute of domain class not being recognized in grails template? -

i have grails template _questionform.gsp. however, question (which attribute of question domain class) not being recognized in template. can reason?

_questionform.gsp

<g:form action="addquestions" controller="dashboard" method="post">     <br/>      question: <g:textarea name="question" required="required" value="${questioninstance?.question}"/> <br/> //.question not recognized here      <!--for options-->     <g:each in="${(1..<5)}" var="i">         option ${i} : <g:textfield name="option${i}" required="required" class="options"/> <br/>     </g:each>      subject: <g:select name="questionsubject"                        from="${com.dwit.research.begnas.api.subject.list()}"                        optionvalue="subject"                        optionkey="id" noselection="['':'choose subject']" required="required"/>     <br/><br/>      <em>correct answer: </em><br/>     <!--for correct answer-->     <g:each in="${(1..<5)}" var="i">         <input type="radio" name="correct_answer" value="${i}" id="rdo_option${i}"/> <label for="rdo_option${i}">option ${i}</label><br/>     </g:each>     <br/>     <g:submitbutton name="next"/> </g:form> 

question (domain class)

package com.dwit.research.begnas.api

class question {

string question boolean isskipped = false subject subject  static constraints = { } 

}

the problem questioninstance variable set string rather instance of question.

1. look @ controller renders _questionform.gsp.
2. there's render() method call sets view , model.
3. change model.questioninstance instance of question.