这样？<script language="JavaScript" type="text/JavaScript">
function test()
{
awaysrain.innerHTML="<input type=\"text\" name=\"aaa\">"
}
</script>
</head><body>
<form name="form1" method="post" action="">
<table width="410" border="0" cellspacing="0" cellpadding="5">
<tr>
<td width="13%" height="33"> <select name="select1" onChange="test()">
<option value="cjj">cjj</option>
<option value="xuii">xuii</option>
<option value="luzg">luzg</option>
<option value="tomcat_jmx">tomcat_jmx</option>
</select></td>
<td width="87%" nowrap><div id="awaysrain"></div></td>
</tr>
</table>
</form>
function test()
{
awaysrain.innerHTML="<input type=\"text\" name=\"aaa\">"
}
</script>
</head><body>
<form name="form1" method="post" action="">
<table width="410" border="0" cellspacing="0" cellpadding="5">
<tr>
<td width="13%" height="33"> <select name="select1" onChange="test()">
<option value="cjj">cjj</option>
<option value="xuii">xuii</option>
<option value="luzg">luzg</option>
<option value="tomcat_jmx">tomcat_jmx</option>
</select></td>
<td width="87%" nowrap><div id="awaysrain"></div></td>
</tr>
</table>
</form>
function test()
{
awaysrain.innerHTML="<input type=\"text\" name=\"aaa\" value=\"" + form1.select1.value + "\">"
}
</script>
</head><body>
<form name="form1" method="post" action="">
<table border="0" cellspacing="0" cellpadding="5">
<tr>
<td width="13%" height="33"> <select name="select1" onChange="test()">
<option value="cjj">cjj</option>
<option value="xuii">xuii</option>
<option value="luzg">luzg</option>
<option value="tomcat_jmx">tomcat_jmx</option>
</select></td>
<td width="87%" nowrap><div id="awaysrain"></div></td>
</tr>
</table>
</form>
function Add(){
if(document.all('newEle')==null){
var oNewItem = document.createElement("INPUT");
oNewItem.id="newEle"
S1.insertAdjacentElement("afterEnd",oNewItem);
}
}
</SCRIPT><BODY>
<SELECT ID = "S1" onChange="Add()">
<option value="cjj">cjj</option>
<option value="xuii">xuii</option>
<option value="luzg">luzg</option>
<option value="tomcat_jmx">tomcat_jmx</option>
</select><INPUT TYPE = "button" VALUE = "none"></BODY>
function test()
{
awaysrain.innerHTML="<input type=\"text\" name=\"aaa\" value=\"" + form1.select1.value + "\">"
}
</script>
</head><body>
<form name="form1" method="post" action="">
<table border="0" cellspacing="0" cellpadding="5">
<tr>
<td width="13%" height="33"> <select name="select1" onChange="test()">
<option value="cjj">cjj</option>
<option value="xuii">xuii</option>
<option value="luzg">luzg</option>
<option value="tomcat_jmx">tomcat_jmx</option>
</select></td>
<td width="87%" nowrap><div id="awaysrain"></div></td>
</tr>
</table>
</form>
<head>
<script type="text/javascript">
if (document.getElementById){
document.write('<style type="text/css">\n')
document.write('.dropcontent{display:none;}\n')
document.write('</style>\n')
}function contractall(){
if (document.getElementById){
var inc=0
while (document.getElementById("dropmsg"+inc)){
document.getElementById("dropmsg"+inc).style.display="none"
inc++
}
}
}function expandone(){
if (document.getElementById){
var selectedItem=document.dropmsgform.dropmsgoption.selectedIndex
contractall()
document.getElementById("dropmsg"+selectedItem).style.display="block"
}
}if (window.addEventListener)
window.addEventListener("load", expandone, false)
else if (window.attachEvent)
window.attachEvent("onload", expandone)</script></head><body><form name="dropmsgform">
<select name="dropmsgoption" size="1" style="width:300" onChange="expandone()">
<option selected>What is JavaScript?</option>
<option>Difference betwen Java and JavaScript</option>
<option>What is DHTML?</option>
</select>
<br><div id="dropmsg0" class="dropcontent">
JavaScript is a scripting language originally adfs asdf asdf
</div><div id="dropmsg1" class="dropcontent">
adsf asdf asdf asd fasdf fdas asdf asd fasdf
</div><div id="dropmsg2" class="dropcontent">
asdf asdf asdf sdf asdf as
</div></form></body>
</html>