how to create another (textbox/combobox) dynamically when i click a button with simple mvc

       <button id="btnGenRow" ></button>
       <grid sizedByContent="true" sclass="grid-no-effect" style="background: none;"   oddRowSclass="none">
                  <columns vflex="1" >
                            <column style="min-width:240px" align="left" ></column>
                            <column style="min-width:200px" align="left" ></column>
                            <column style="min-width:120px" align="center" ></column>
                  </columns>
                  <rows id="attachRows" >
                       <row >
                             <combobox id="cmbAttachType" style="min-width: 100px" />
                             <textbox id="txtAttachname" style="min-width: 120px" />
                             <button id="btnSelectAttach" width="90px" />
                       </row>
                  </rows>
        </grid>

         for (Rows r: attachRows) {
            for (Component component : r.getChildren()) {
                Row row = (Row) component;
                row.appendChild(new Label("hello"));

                r.appendChild(row);
            }
        }