Tag [findall] does not exist. No tag library found for namespace: g

[atan742]

Title told itself. I am using grails 2.0.1 and I get this error while using this code.

I want to display the corresponding office name (which is listed in office lists) of office code saved in the user list:

<g:each in="${ userList }" var="i">
<br />
<p><strong>${ i.username }</strong></p>
<g:findall in="${ offices }" expr="it.officeCode == '${ i.officeCode }'">Office Code: ${ it.office }<br /></g:findall>
</g:each>

-> where officeCode has exactly one correspondent in offices; offices has the property [office, officeCode]

Thanks in advance!