<a href="b.jsp?name1=值"></a>

<%
   String name2 = new String(request.getParameter("name1").getBytes("ISO-8859-1"),"GBK");
   request.setAttribute("name3",name2);
%>
<input id="id1" value="${name3}"/>

<script>
  var href = "b.jsp?sd=";
  var getV = function(){
    var add = $("#ad").val();
    href = href + add;
  }
  var h1 = function(){
  　　window.location = href;
　　}
</script>
<select id="ad" onChange="getV()"></select>
<a id="h" href="#" onClick="hl()" ></a>