problem with t:tree

[merve klug]

hi,
i tried the code that i found in coderanch archive but i am getting error page with the error:

org.apache.jasper.JasperException: java.lang.IllegalArgumentException: Component javax.faces.component.UIViewRoot is no org.apache.myfaces.custom.tree.HtmlTree

i nearly tried codes on this page:

https://coderanch.com/t/212408/JSF/java/work-tree-component#1015178

i have only changed as:

<managed-property>
            <property-name>tree</property-name>
            <property-class>org.apache.myfaces.custom.tree.model.DefaultTreeModel</property-class>
            <null-value/>
        </managed-property>

what should i do
thanks

[merve klug]

the problem has been resolved.
i had remembered to add

<%@taglib uri="http://myfaces.apache.org/tomahawk" prefix="t"%>

but had forgotten to add:

<%@taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
    <%@taglib uri="http://java.sun.com/jsf/core" prefix="f" %>

sorry for unnecessary content