怎样使input(text) 显示 select 的选定值

<script language="javascript">
function Changesel(){
window.form1.showsel.value=window.form1.selects.value;
}
</script>
<form name="form1" method="post">
<input id="showsel" type="text" name="showvalue">
<select name="selects" onChange="Changesel()">
<option value="NO1">NO1</option>
<option value="NO2">NO2</option>
<option value="NO3">NO3</option>
<option value="NO4">NO4</option>
</select>
</form>

希望能解决你的问题

<script language="javascript">
function setvalue(a)
{
document.form1.haha.value=a;
}
</script>
<form name="form1">
<input type="text" name="haha">
<select name="