js增加行

<ul id="fwtable" class="items">
<li>

定义一个隐藏控件记录行数
<input type="hidden" name="jsfw" value="new1" />
<label class="itm"><strong>*</strong>附件上传：</label><span class="item"><asp:FileUpload ID="FileAttach1" runat="server" /></span>

</li>
</ul>

function addRow() {

//定义html
var gshtml = "";

//最后的数值，id
var lastIndex;
if ($("input:hidden[name='jsfw']").size() > 0) {
var lastnew = $("input:hidden[name='jsfw']:last").val();
lastIndex = parseInt(lastnew.substr(3)) + 1;
} else {
lastIndex = 1;
}

//拼接html
gshtml += '<li id=' + (lastIndex + 5) + '><input type="hidden" name="jsfw" value="new' + lastIndex + '" /><label class="itm"><strong></strong></label><span class="item"><input id="FileAttach' + lastIndex + '" type="file" /><button onclick="del(' + (lastIndex + 5) + ');"> - </button></span></li>';

//将拼接的html加到容器，例子中为ul
$("#fwtable").append(gshtml);
}