js动态添加删除table中的行

<mce:script language="javascript" type="text/javascript"><!--
function $g(id){
return document.getElementById(id);
}
function ClickItem(obj){
var table = $g("task_list");
var tbody = $g("task_list").childNodes[0];
//var obj_item = obj.parentNode.parentNode.getElementsByTagName("td");
var tr = $g("tr_"+obj.value);
if(obj.checked){
if(tr == null){
var curr_row = obj.parentNode.parentNode;
var newRow = table.insertRow(-1);
newRow.id = "tr_"+obj.value+"";
for(var i=0; i < curr_row.cells.length;i++){
var cel = curr_row.cells[i];
var newCel = newRow.insertCell(-1);
if(i == 0){ //第一个单元格
var input;
if(window.ActiveXObject){
input = document.createElement("<input type='checkbox' name='check' checked='checked'>");
}
else{
input = document.createElement("input");
input.setAttribute("type","checkbox");
input.setAttribute("checked","true");
}
input.setAttribute("disabled","true");
newCel.appendChild(input);
newCel.appendChild(document.createTextNode(" "+obj.value));
}
else{
if (i != curr_row.cells.length-1 ){ //最后一个单元格不添加任何内容
newCel.setAttribute("align","center");
newCel.innerHTML = cel.innerHTML;
}
}
}
}
}
else{
if(tr != null){
tbody.removeChild(tr);
}
}
}
// --></mce:script>

<input name="chk_id" id="chk_id" type="checkbox" value="1" onclick="ClickItem(this);" />