<script src="jquery-1.2.1.js" type="text/网页特效"></script> <script language="javascript" type="text/javascript"> $(document).ready(function(){ $("#selecttest").change(function() {        //alert("hello");        //alert($("#selecttest").attr("name"));        //$("a").attr("href","xx.html");        //window.location.href="xx.html";        //alert($("#selecttest").val());        alert($("#selecttest option[@selected]").text());        $("#selecttest").attr("value", "2"); }); }); </script> <a href="#">aaass</a> [b]<!--下拉框--> [/b]<select id="selecttest" name="selecttest"> <option value="1">11</option> <option value="2">22</option> <option value="3">33</option> <option value="4">44</option> <option value="5">55</option> <option value="6">66</option> </select> [b]方法二 [/b]function autoscrollregion() {         var reg_name = $("#<%=txt_reg_name.clientid%>").val();         $("#<%=ddl_xreg_id.clientid%> option").each(function() {         if ($(this).text() == reg_name) {                 $(this).attr("selected", "selected");                 break;             }         });          }