很实用的东西，呵呵
运行代码框<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <META content="fason,阿信" name=Author> <title>动态提示的下拉框</title> <style> a{color:red;text-decoration:none;font-size:12px} </style> </head> <body onload="Init()"> <center> <h2>动态提示的下拉框</h2> <hr> <form name=frm> <table> <tr> <td>请输入1或2或3或4或5进行测试：<br><input name="txt" style="width:100px" onkeyup="SelectTip(0)"> <input type="button" value="reset" onclick="SelectTip(1)"></td> </tr> <tr> <td> <span id="demo"><select name="demo" style="width:100px" size=10 onchange="txt.value=options[selectedIndex].text;"> <option value="1">1</option> <option value="12">12</option> <option value="123">123</option> <option value="1234">1234</option> <option value="2">2</option> <option value="23">23</option> <option value="234">234</option> <option value="2345">2345</option> <option value="3">3</option> <option value="34">34</option> <option value="345">345</option> <option value="3456">3456</option> <option value="5">5</option> <option value="51">51</option> <option value="51w">51w</option> <option value="51wi">51wi</option> <option value="51win">51win</option> <option value="51windows">51windows</option> </select></span> </td> </tr> </form> </table> <hr> <script language="javascript"> var TempArr=[];//存贮option function Init(){ var SelectObj=document.frm.elements["demo"] /*先将数据存入数组*/ with(SelectObj) for(i=0;i<length;i++)TempArr[i]=[options[i].text,options[i].value] } function SelectTip(flag){ var TxtObj=document.frm.elements["txt"] var SelectObj=document.getElementById("demo") var Arr=[] with(SelectObj){ var SelectHTML=innerHTML.match(/<[^>]*>/)[0] for(i=0;i<TempArr.length;i++) if(TempArr[i][0].indexOf(TxtObj.value)==0||flag)//若找到以txt的内容开头的，添option。若flag为true,对下拉框初始化 Arr[Arr.length]="<option value='"+TempArr[i][1]+"'>"+TempArr[i][0]+"</option>" innerHTML=SelectHTML+Arr.join()+"</SELECT>" } } </script> </body> [Ctrl+A 全部选择 提示：你可先修改部分代码，再按运行]
