<SELECT id="select1" size="9">
<OPTION value="0">0</OPTION>
<option value="1">1</option>
</SELECT>
<SELECT id="select2" size="9">
<OPTION value="0">0</OPTION>
</SELECT>
<INPUT type="button" value="添加" id="bt" onclick="selectit()">
<script language="JavaScript">
<!--
function selectit()
{
var s1 = document.all.select1;
var s2 = document.all.select2;
var val = s1.options[s1.selectedIndex].value;
for(var i=0;i<s2.length;i++)
{
if(s2[i].value == val)
alert("select2里巳经有这个值了")
}
}//-->
</script>
<OPTION value="0">0</OPTION>
<option value="1">1</option>
</SELECT>
<SELECT id="select2" size="9">
<OPTION value="0">0</OPTION>
</SELECT>
<INPUT type="button" value="添加" id="bt" onclick="selectit()">
<script language="JavaScript">
<!--
function selectit()
{
var s1 = document.all.select1;
var s2 = document.all.select2;
var val = s1.options[s1.selectedIndex].value;
for(var i=0;i<s2.length;i++)
{
if(s2[i].value == val)
alert("select2里巳经有这个值了")
}
}//-->
</script>
if(document.forms[0].select2.options[i].value==document.forms[0].select1.value){
alert("find");
}
}
function selectit()
{
for(k=0;k<aa.select2.options.length;k++)
{
if (aa.select1.value==aa.select2.options[k].value)
{
alert('你添加的值已有');
return false;
}
}
aa.select2.options.length=aa.select2.options.length+1;
aa.select2.options[2].text=aa.select1.value;
aa.select2.options[2].value=aa.select1.value;
alert('ok');
return false;
}
</script>
<form name="aa" onsubmit="return selectit();">
<select name="select1">
<option value=1>1</option>
<option value=2>2</option>
<option value=3>3</option>
</select>
<select name="select2">
<option value=1>1</option>
<option value=2>2</option>
</select>
</script>
<input name=sfd type=submit>
</form>