<div class="fl shop-num ml24"><input type="button" style=" border-right:0px;" onClick="disNum(this)" value="-"><input type="text" value="1"  οnkeyup="value=value.replace(/[^\d]/g,'1')"/><input type="button" value="+" style="border-left:0px;" onClick="incNum(this)"></div>

//text只能输入数字

<script>

function disNum(dom){

var disNum=dom.nextSibling.value;

if(disNum<2)//防止数量少于1

{

dom.nextSibling.value=1;

}

else

{

dom.nextSibling.value--;

}

}

function incNum(dom){

dom.previousSibling.value ++;

}

</script>