<script language="javascript">
function addrows(){
var len = optionlist.rows.length; //得到table的行数
var obj = optionlist.insertRow(len);//在最后一行插入
/**插入第一列**/
obj.insertCell(0);
obj.cells(0).innerHTML="选项" + (len+1) + "：<input type=text name=option size=28>";
}
function deleterow(){
var len = optionlist.rows.length;
if(len <= 1) {
alert("至少要有一个选项");
}
else {
optionlist.deleteRow(len-1);//删除最后一项
}
}
function getOptionCount(){
return optionlist.rows.length;
}
</script>

<input type="button" id="bt1" value="添加选项" onClick="addrows();">
<input type="button" id="bt2" value="删除选项" onClick="deleterow();">

<table id="optionlist">
</table>