А не проще сгенерить эти элементы?
<html>
<head>
<meta charset="windows-1251" />
<style>
#wr {
margin: 50px;
position: relative;
border: 2px solid #06c106;
padding: 5px 10px;
width: 130px;
overflow: hidden;
}
#wr input {
display: block;
padding: 8px;
width: 50px;
text-align: center;
border: 2px solid #c00;
outline: none;
float: left;
}
.minus,
.plus {
float: left;
display: block;
font-size: 26px;
padding: 5px 8px;
font-weight: bolder;
cursor: pointer;
color: #d00;
-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
}
</style>
</head>
<body>
<div id="wr"></div>
<script>
create=function(){
var minus=document.createElement("span")
minus.className="minus"
minus.innerHTML="-"
minus.onclick=function(){var iv=input.value; input.value=parseInt(iv)==0? iv : iv.replace(/\d+/, function(n){return +n-1})}
wr.appendChild(minus)
var input=document.createElement("input")
input.value="1 шт"
wr.appendChild(input)
var plus=document.createElement("span")
plus.innerHTML="+"
plus.className="plus"
plus.onclick=function(){input.value=input.value.replace(/\d+/, function(n){return +n+1})}
wr.appendChild(plus)
}
create()
create()
create()
create()
</script>
</body>
</html>