正则表达式验证必须小于12位数字?解决方案

正则表达式验证必须小于12位数字?
<TD bgColor=#61cefc colSpan=4 align=middle>企业组织机构代码</TD>
<TD>
<Select Type="text" name="select_11" id="select_11" Style="WIDTH: 140px" >
<Option selected value="-1" name="select_0_0" id="select_0_0">请选择</Option>
<Option value="未办理" name="select_0_1" id="select_0_1">未办理</Option>
<Option value="已办理" name="select_0_2" id="select_0_2">已办理
</Option>
</Select>
<input type="text" value="" "style="display:none"> 
</TD>
如何当select里选择已办理时 显示隐藏的文本框 并输入企业组织机构代码，选择未办理时 隐藏文本框的值为未办理

[解决办法]

JScript code

function banli(){    var select_11 = document.getElementById("select_11");    var test = document.getElementById("test");    if(select_11.value=="bbb"){        test.style.display = "block";        test.value = "";    }else if(select_11.value=="aaa"){        test.style.display = "block";        test.value = select_11.value;        test.readonly = "readonly";    }else{        test.style.display = "none";    }}
[解决办法]
验证小于12的js，用正则了，你稍微改一下就能用了
JScript code
function isURL(strURL){    var reg2 = /^([0-9]{1,12})?$/g       if (reg2.test(strURL)){        return true;         }else{           return false;         }}function check(){   var myurl = document.getElementById("myurl").value;   if(isURL(myurl)){    alert(myurl+"\nright");   }else{    alert(myurl+"\nwrong");   }}<input type="text" id="myurl" value="55555"><a href="javascript:check()">test</a>