<select id="s">
<option>a</option>
<option>b</option>
<option>c</option>
</select>
<input id="i"><input type="button" onclick="c()" value="改变">
<script>
so = document.getElementById("s");
io = document.getElementById("i");
function c()
{
for(co=0;co<so.length;co++)
{
if(so.options[co].text==io.value) so.selectedIndex=co;
}
}
</script>
<option>a</option>
<option>b</option>
<option>c</option>
</select>
<input id="i"><input type="button" onclick="c()" value="改变">
<script>
so = document.getElementById("s");
io = document.getElementById("i");
function c()
{
for(co=0;co<so.length;co++)
{
if(so.options[co].text==io.value) so.selectedIndex=co;
}
}
</script>
<head>
<script language="javascript">
function selectChange()
{
document.all.text.value = document.all.select.value;
}
</script>
</head>
<body>
<div>
<select id='select' style="position:absolute;width:150px;clip: rect(0 180 110 130)" onchange="selectChange()">
<option value='1'> 1 </option>
<option value='2'> 2 </option>
<option value='3'> 3 </option>
<option value='4'> 4 </option>
</select>
<input type='text' id='text'style="position:absolute;width:150px;" value="1" onfocus="this.value='';document.all.select.value='';">
</div>
</body>
</html>
用alert(document.all.select.value)不能取得正确的值？