<table>
<tr>
<td>1</td>
<td><span onclick="changeNum(this,1)" style="cursor:pointer;">+</span><input type="text" /><span onclick="changeNum(this,-1)" style="cursor:pointer;">-</span></td>
</tr>
<tr>
<td>2</td>
<td><span onclick="changeNum(this,1)" style="cursor:pointer;">+</span><input type="text" /><span onclick="changeNum(this,-1)" style="cursor:pointer;">-</span></td>
</tr>
<tr>
<td>3</td>
<td><span onclick="changeNum(this,1)" style="cursor:pointer;">+</span><input type="text" /><span onclick="changeNum(this,-1)" style="cursor:pointer;">-</span></td>
</tr>
</table>
<script type="text/javascript">
function changeNum(obj,num)
{
var input = getParent(obj).getElementsByTagName("input");
for(var i=0;i<input.length;i++)
{
if(input[i].type=="text")
{
if(input[i].value == "")
input[i].value = num;
else
input[i].value = input[i].value - 0 + num;
}
}
}
//获取父级对像
function getParent(obj)
{
if(typeof(obj) != "object"){obj = document.getElementById(obj);}
if(obj)
return obj.parentElement || obj.parentNode;
}
</script>
var input = getParent(obj).getElementsByTagName("input"),v;
for (var i = 0; i < input.length; i++) {
if (input[i].type == "text") {
//////////////////////////
v = input[i].value;
if (v == '') v = 0;
v = parseInt(v, 10) + num;
if (v < 0) v = 0;
//////////////////////////
input[i].value=v
}
}
}