title: variable in iframe with zk
body: <p>i have a for each in my zk page, and in the each i am creating a column, and in my column i need add a iframe, and to each frame i need pass as variable the label of the column.</p>
  
  <p>I have something like:</p>
  
  <pre><code>&lt;zk&gt;
            &lt;window title="Dynamic Columns" border="normal" width="1824px" apply="org.zkoss.bind.BindComposer" viewModel="@id('vm') @init('pkg$.DynamicColumnModel')"&gt;
  &lt;grid &gt;
  
                 &lt;columns&gt;
                    &lt;column forEach="${vm.columnList}" label="${each}"&gt;
  
                &lt;iframe 
          src="test.zul" /&gt;
                  &lt;/column&gt;
                &lt;/columns&gt;
       &lt;/grid&gt;
     &lt;/window&gt;
  &lt;/zk&gt;
  </code></pre>
  
  <p>But i have an error when i include the page, and my first problem is that i do not know how can i pass a variable to each iframe.</p>
  
  <p>And my java is something like: </p>
  
  <pre><code>public class DynamicColumnModel {
  
  private List&lt;String&gt; columnList = new ArrayList&lt;String&gt;();
   private String texto="123";
  
  @Init
  public void init(){
  
      columnList.add("Dynamic Col A");
      columnList.add("Dynamic Col B");
      columnList.add("Dynamic Col C");
      columnList.add("Dynamic Col D");
  }
  
  public List&lt;String&gt; getColumnList() {
      return columnList;
  }
  public void setColumnList(List&lt;String&gt; columnList) {
      this.columnList = columnList;
  }
  
   public String getTexto() {
      return texto;
  }
  public void setTexto(String texto) {
      this.texto = texto;
  }
  
  
  @Command
     public void mensaje(){
  
    }
  
  }
  </code></pre>
  
  <p>Thanks</p>