我想实现这样的功能:
在下拉框里(s_city)选择一项之后 在 文本框里出现对应的值(txt_name)
注意:文本框的值是通过数据库调出来的 页面最好是不刷新的

哪个高手帮我下啊 javascript或者 vbscript 都可以

<script language="JavaScript">
<!--
//二级菜单
var hw_selecttext ="北京|东城^西城^崇文^宣武^朝阳^丰台^石景山^海淀^门头沟^房山^通州^顺义^昌平^大兴^平谷^怀柔^密云^延庆*上海|黄浦^卢湾^徐汇^长宁^静安^普陀^闸北^虹口^杨浦^闵行^宝山^嘉定^浦东^金山^松江^青浦^南汇^奉贤^崇明*天津|和平^东丽^河东^西青^河西^津南^南开^北辰^河北^武清^红挢^塘沽^汉沽^大港^宁河^静海^宝坻^蓟县*重庆|万州^涪陵^渝中^大渡口^江北^沙坪坝^九龙坡^南岸^北碚^万盛^双挢^渝北^巴南^黔江^长寿^綦江^潼南^铜梁^大足^荣昌^壁山^梁平^城口^丰都^垫江^武隆^忠县^开县^云阳^奉节^巫山^巫溪^石柱^秀山^酉阳^彭水^江津^合川^永川^南川*河北|石家庄^邯郸^邢台^保定^张家口^承德^廊坊^唐山^秦皇岛^沧州^衡水*山西|太原^大同^阳泉^长治^晋城^朔州^吕梁^忻州^晋中^临汾^运城*内蒙古|呼和浩特^包头^乌海^赤峰^呼伦贝尔盟^阿拉善盟^哲里木盟^兴安盟^乌兰察布盟^锡林郭勒盟^巴彦淖尔盟^伊克昭盟*辽宁|沈阳^大连^鞍山^抚顺^本溪^丹东^锦州^营口^阜新^辽阳^盘锦^铁岭^朝阳^葫芦岛*吉林|长春^吉林^四平^辽源^通化^白山^松原^白城^延边*黑龙江|哈尔滨^齐齐哈尔^牡丹江^佳木斯^大庆^绥化^鹤岗^鸡西^黑河^双鸭山^伊春^七台河^大兴安岭*江苏|南京^镇江^苏州^南通^扬州^盐城^徐州^连云港^常州^无锡^宿迁^泰州^淮安*浙江|杭州^宁波^温州^嘉兴^湖州^绍兴^金华^衢州^舟山^台州^丽水*安徽|合肥^芜湖^蚌埠^马鞍山^淮北^铜陵^安庆^黄山^滁州^宿州^池州^淮南^巢湖^阜阳^六安^宣城^亳州*福建|福州^厦门^莆田^三明^泉州^漳州^南平^龙岩^宁德*江西|南昌市^景德镇^九江^鹰潭^萍乡^新馀^赣州^吉安^宜春^抚州^上饶*山东|济南^青岛^淄博^枣庄^东营^烟台^潍坊^济宁^泰安^威海^日照^莱芜^临沂^德州^聊城^滨州^菏泽*河南|郑州^开封^洛阳^平顶山^安阳^鹤壁^新乡^焦作^濮阳^许昌^漯河^三门峡^南阳^商丘^信阳^周口^驻马店^济源*湖北|武汉^宜昌^荆州^襄樊^黄石^荆门^黄冈^十堰^恩施^潜江^天门^仙桃^随州^咸宁^孝感^鄂州*湖南|长沙^常德^株洲^湘潭^衡阳^岳阳^邵阳^益阳^娄底^怀化^郴州^永州^湘西^张家界*广东|广州^深圳^珠海^汕头^东莞^中山^佛山^韶关^江门^湛江^茂名^肇庆^惠州^梅州^汕尾^河源^阳江^清远^潮州^揭阳^云浮*广西|南宁^柳州^桂林^梧州^北海^防城港^钦州^贵港^玉林^南宁地区^柳州地区^贺州^百色^河池*海南|海口^三亚*四川|成都^绵阳^德阳^自贡^攀枝花^广元^内江^乐山^南充^宜宾^广安^达川^雅安^眉山^甘孜^凉山^泸州*贵州|贵阳^六盘水^遵义^安顺^铜仁^黔西南^毕节^黔东南^黔南*云南|昆明^大理^曲靖^玉溪^昭通^楚雄^红河^文山^思茅^西双版纳^保山^德宏^丽江^怒江^迪庆^临沧*西藏|拉萨^日喀则^山南^林芝^昌都^阿里^那曲*陕西|西安^宝鸡^咸阳^铜川^渭南^延安^榆林^汉中^安康^商洛*甘肃|兰州^嘉峪关^金昌^白银^天水^酒泉^张掖^武威^定西^陇南^平凉^庆阳^临夏^甘南*宁夏|银川^石嘴山^吴忠^固原*青海|西宁^海东^海南^海北^黄南^玉树^果洛^海西*新疆|乌鲁木齐^石河子^克拉玛依^伊犁^巴音郭勒^昌吉^克孜勒苏柯尔克孜^博尔塔拉^吐鲁番^哈密^喀什^和田^阿克苏*香港|*澳门|*台湾|台北^高雄^台中^台南^屏东^南投^云林^新竹^彰化^苗栗^嘉义^花莲^桃园^宜兰^基隆^台东^金门^马祖^澎湖*其它|北美洲^南美洲^亚洲^非洲^欧洲^大洋洲"
//如果文本与值不同，请输入在文本后加上@值,如:北京@010|东城@001^西城@002
var TheSplit1 = "*" //北京与上海的分隔符
var TheSplit2 = "|" //北京与东城的分隔符
var TheSplit3 = "^" //东城与西城的分隔符
var TheSplit4 = "@" //文本与值的分隔符，可以省略
var hwallselecttext = hw_selecttext
var hwdefault_value = "山东济宁"

//默认值，在值有相同时有bug。

document.write('<select name="hw_1" onChange = "hw_select()"></select> <select name="hw_2" onChange = "hw_select()"></select> <input class="input" size="15" type="input" value="'+hwdefault_value+'" name="hw">\n');
var hwallselecttextarr
hwallselecttextarr = hwallselecttext.split(TheSplit1)
hwArraylength = hwallselecttextarr.length
var hwwhere = new Array(hwArraylength);
hwwhere[0]= new hw_comefrom("请选择@","请选择@");

for (var hwl=0;hwl<hwArraylength;hwl++)
{
eval(hwwhere[hwl+1] = new hw_comefrom(hwallselecttextarr[hwl].split(TheSplit2)[0],hwallselecttextarr[hwl].split(TheSplit2)[1]))
}
function hw_comefrom(hwSelect_s1,hwSelect_s2) { this.hwSelect_s1 = hwSelect_s1; this.hwSelect_s2 = hwSelect_s2; }

function hw_select()
{
with(document.all.hw_1)
{
var hwSelect_s12 = options[selectedIndex].value;
}
for(hwi = 0;hwi < hwwhere.length;hwi ++)
{
if (hwwhere[hwi].hwSelect_s1.indexOf(TheSplit4)!=-1)
{
var hwThisV = hwwhere[hwi].hwSelect_s1.split(TheSplit4)[1]
}
else
{
var hwThisV = hwwhere[hwi].hwSelect_s1
}
if (hwThisV == hwSelect_s12)
{
hwSelect_s13 = (hwwhere[hwi].hwSelect_s2).split(TheSplit3);
for(hwj = 0;hwj < hwSelect_s13.length;hwj++)
{
with(document.all.hw_2)
{
length = hwSelect_s13.length;
if (hwSelect_s13[hwj].indexOf(TheSplit4)!=-1)
{
options[hwj].text = hwSelect_s13[hwj].split(TheSplit4)[0]
options[hwj].value = hwSelect_s13[hwj].split(TheSplit4)[1]
}
else
{
options[hwj].text = hwSelect_s13[hwj];
options[hwj].value = hwSelect_s13[hwj];
}
var hwSelect_s14=options[selectedIndex].value;
}
}
break;
}
}
document.all.hw.value=hwSelect_s12+""+hwSelect_s14;
}
function hw_init()
{
with(document.all.hw_1)
{
length = hwwhere.length;
var hwm = 0
for(hwk=0;hwk<hwwhere.length;hwk++)
{
if (hwwhere[hwk].hwSelect_s1.indexOf(TheSplit4)!=-1)
{
options[hwk].text = hwwhere[hwk].hwSelect_s1.split(TheSplit4)[0];
options[hwk].value = hwwhere[hwk].hwSelect_s1.split(TheSplit4)[1];
if (hwdefault_value.indexOf(hwwhere[hwk].hwSelect_s1.split(TheSplit4)[1])!=-1){hwm = hwk}
}
else
{
options[hwk].text = hwwhere[hwk].hwSelect_s1;
options[hwk].value = hwwhere[hwk].hwSelect_s1;
if (hwdefault_value.indexOf(hwwhere[hwk].hwSelect_s1)!=-1){hwm = hwk}
}
}
selectedIndex = hwm
}
with(document.all.hw_2)
{
var hwn = 0
hwSelect_s13 = (hwwhere[hwm].hwSelect_s2).split(TheSplit3);
length = hwSelect_s13.length;
for(hwl=0;hwl<length;hwl++)
{
if (hwSelect_s13[hwl].indexOf(TheSplit4)!=-1)
{
options[hwl].text = hwSelect_s13[hwl].split(TheSplit4)[0];
options[hwl].value = hwSelect_s13[hwl].split(TheSplit4)[1];
if (hwdefault_value.indexOf(hwSelect_s13[hwl].split(TheSplit4)[1])!=-1){hwn = hwl}
}
else
{
options[hwl].text = hwSelect_s13[hwl];
options[hwl].value = hwSelect_s13[hwl];
if (hwdefault_value.indexOf(hwSelect_s13[hwl])!=-1){hwn = hwl}
}
}
selectedIndex = hwn
}
}
hw_init();
//-->
</script>