How to retrieve information from an action class in the jelly file associated

[obama]

Hello, I have been trying to create a plugin that would be able to display 
information in a new page accessible from the main panel.
I have implemented the action interface and created the jelly file to 
display.
 
My class action looks like something like that:
 
public class LinkAction implements Action {
    private String data;
    private String url, name, icon;
       
    @DataBoundConstructor
    public LinkAction() {
    }
    
    public String getUrlName()
    {
        return url;
    }
    public String getDisplayName()
    {
        return text;
    }
    public String getIconFileName()
    {
        return icon";
    }
}
 
and my Index.jelly file like that :
 
<?jelly escape-by-default='true'?>
<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" 
xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" 
xmlns:f="/lib/form" xmlns:s="/lib/samples">
  <l:layout title="New page">
    <l:main-panel>
      <h1>Title</h1>
        <f:entry title="${it.data}">
           <f:textbox name="name" value="whatever"/>
        </f:entry>
    </l:main-panel>
  </l:layout>
</j:jelly>
The page created only displays until it reaches the textbox, which it does 
not display.
Does anyone knows how to retreive data from the Action Class, and also how 
to send data to it.
I have been looking for an anwser for this for quite a while now, so I 
would really apreciate if someone could tell me.
 
Thank you