<table border="0" cellspacing="0" cellpadding="0"> 

  <tbody id="tbody">

    <tr> 

      <td><input type="text" name="text1" /></td> 

      <td><input type="text" name="text2" /></td> 

      <td><select name="select"> 

        <option>item1</option> 

        <option>item2</option> 

        <option>item3</option> 

        <option>item4</option> 

        <option>item5</option>

      </select></td>

      <td><input type="button" value="Remove" onclick="removeRow(this.parentNode.parentNode)"></td>

    </tr></tbody>

  </table>

  <input name="button" type="button" value="Add row" onclick="addRow(')">

function addRow()

{ 

    var root = document.getElementById("tbody");

    var allRows = root.getElementsByTagName('tr');

    var cRow = allRows[0].cloneNode(true)

    root.appendChild(cRow);

} 

function removeRow(r)

{

    var root = r.parentNode;

    var allRows = root.getElementsByTagName('tr')

    if(allRows.length>1)

        root.removeChild(r);

    else

        alert("only one row left, you not need to remove it.");

}