纯javascript写的动态添加删除行

<div id="testR">
<select id="cfo" name="columnDefineInfo" style="display:none">
<c:forEach var="dcDefine" items="${decisionColumnDefineList}" varStatus="status">
<option value="<c:out value="${dcDefine.columnDefineId}"/>"><c:out value="${dcDefine.columnName}" /></option>
</c:forEach>
</select>

</div>
<table id="mytable" width="100%" border="0" cellspacing="1" cellpadding="2" align="center" class="etable">
             <TR align="center">
                    <TD class="content" colspan="4">
                        <b>条件列信息</b>
                    </TD>
                </TR>
              <TR align="left">
              <td colspan="4">
              <input type="button" name="tpbutton" value="增 加" onclick="addTableRow();" />
              </td>
              </TR>
</table>
<script languge="javascript">
var infoNum=0;
var ruleFactNum=0;
/**
     * 功能：select对象动态添加Options项
     * @param {} objSelectNow select对象
     * @param {} txt    显示值text
     * @param {} val    值value
     */ 
function addOption(objSelectNow, txt, val) { 
        // / 使用W3C标准语法为SELECT添加Option 
        var objOption = document.createElement("option"); 
        objOption.text = txt; 
        objOption.value = val; 
        objSelectNow.options.add(objOption); 
    }
  /**
     * 功能：动态添加行
     */   
function addTableRow() {  
var listTable = document.getElementById('mytable');
var row = listTable.insertRow(listTable.rows.length);
var cells = new Array(1);
for(var i = 0;i < cells.length;i++){
cells[i] = row.insertCell();
}
infoNum = infoNum + 1;
//动态添加值开始
var objSel = document.getElementById("cfo");
    var ops = objSel.options;
   
//条件列
var limitFlag0 = document.createElement("<select name='conditionInfo'>");
var delBtn = document.createElement("<input id='"+infoNum+"' name='btnSave' value='删除 ' type='button' class='tpbutton' onclick='javasript:delTableRow(this);'>");
addOption(limitFlag0,"请选择","");
limitFlag0.style.width="300";
for(var i=0; i<ops.length; i++){
    addOption(limitFlag0,ops[i].text,ops[i].value);
cells[0].appendChild(limitFlag0);
    }
    cells[0].appendChild(delBtn);
   
}
/**
     * 功能：动态删除行
     */  
function delTableRow(obj){
var tableObj = document.getElementById("mytable");
      tableObj.deleteRow(obj.parentElement.parentElement.rowIndex);

}
</script>