学步园

 function onChangeType()
  {  
      today = new Date();
         var todayStr = today.getYear();
        if(today.getMonth()<10){
               todayStr=todayStr+"0"+(today.getMonth()+1);<%--加1转换为本地月份,如果月份小于10，就在前面加0补成双位数,日期一样--%>
        }
        else{
           todayStr=todayStr+(today.getMonth()+1);
        }
       
        if(today.getDate()<10){
               todayStr=todayStr+"0"+today.getDate();
        }
        else{
               todayStr=todayStr+today.getDate();
        }
        alert(todayStr);
      var typeName=document.getElementById("dtype").value;
      var lipinid=document.getElementById("presentid").value;
      var length1=document.getElementById("presentid").value.length;
     
      lipinid=lipinid.substring(length1-3,length1);<%--每次截取礼品编号的最后三位，也就是最初生成的序列号--%>
      var presentid=(typeName+lipinid);<%--把截取的字符串加上下拉框选中的值,拼成新的礼品编号--%>
      document.getElementById("presentid").value=(todayStr+presentid);<%--重新赋值--%>
     
  }