请大虾回答一下！

[qingbei]

我用asp写程序，在表单中有一个下拉框，还有一个文本框，请问我想实现：点击下拉框中选中一个值能在文本框中立即显示出来，怎么实现呢？

[qdubit]

可以通过javascript实现，下边是代码：
<SCRIPT LANGUAGE=javascript>
<!--
var prv=new Array()//医院
var cty=new Array()//级别
var khlb=new Array()//类别
function init(){
<%
dim prv,cty,khlb,i,j,k
dim sq1
i=0
//sq1=document.frm.sq.value
set prv=conn.execute("select yy_mingcheng from sale_manage_khda_mbyyda where dy_bianma='"&s_dy_bianma&"' order by yy_mingcheng")
if not prv.eof then
do while not prv.eof
j=0
k=0
%>
prv[<%=i%>]="<%=trim(prv("yy_mingcheng"))%>";
<%
set cty=conn.execute("select yylb_mingcheng from sale_manage_bianma_yylb as a join sale_manage_khda_mbyyda as b on b.yy_leibie=a.yylb_bianma where b.yy_mingcheng = '"&trim(prv("yy_mingcheng"))&"'")
if not cty.eof then%>
cty[<%=i%>]=new Array()
<%do while not cty.eof%>
cty[<%=i%>][<%=j%>]="<%=trim(cty("yylb_mingcheng"))%>"
<%j=j+1
cty.movenext
loop
end if
cty.close :set cty=nothing
%>
<%
set khlb=conn.execute("select khb_shuoming from sale_base_khlx as a join sale_manage_khda_mbyyda as b on b.khb_bianma=a.khb_bianma where b.yy_mingcheng = '"&trim(prv("yy_mingcheng"))&"'")
if not khlb.eof then%>
khlb[<%=i%>]=new Array()
<%do while not khlb.eof%>
khlb[<%=i%>][<%=k%>]="<%=trim(khlb("khb_shuoming"))%>"
<%k=k+1
khlb.movenext
loop
end if
khlb.close :set khlb=nothing

i=i+1
prv.movenext
loop
end if
prv.close :set prv=nothing
%>
if(prv.length >0){
for(i=0;i<prv.length;i++)
with(document.frm.province)options[length]=new Option(prv[i],prv[i])
document.frm.province.onchange=new Function("go(this.selectedIndex)")
}
}

function go(sIndex){
with(document.frm.city){
length=0;
if(sIndex==0){options[0]=new Option("显示医院级别");return}
for(i=0;i<cty[sIndex-1].length;i++)
options[length]=new Option(cty[sIndex-1][i],cty[sIndex-1][i])
}
with(document.frm.yylb){
length=0;
if(sIndex==0){options[0]=new Option("显示医院类别");return}
for(i=0;i<khlb[sIndex-1].length;i++)
options[length]=new Option(khlb[sIndex-1][i],khlb[sIndex-1][i])
}
}
window.onload=init
-->
</SCRIPT>

[Reker熊]

<select onchange="text1.value=this.options[this.selectedIndex].value">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<input type=text id="text1">