用onChange事件:<SCRIPT LANGUAGE="JavaScript">
function doFun(a, b)
{
b.value = a.value;
}
</SCRIPT><select name="select" onChange="doFun(select, price)">
<option selected>请选择产品</option>
<option value="123">123</option>
<option value="125">125</option>
</select>
<input name="price" type="text" size="8">
function doFun(a, b)
{
b.value = a.value;
}
</SCRIPT><select name="select" onChange="doFun(select, price)">
<option selected>请选择产品</option>
<option value="123">123</option>
<option value="125">125</option>
</select>
<input name="price" type="text" size="8">
function getPrice(obj)
{
document.all.price.value = obj.value;
}
</SCRIPT><select name="select" onChange="getPrice(this)">
<option selected>请选择产品</option>
<option value="1">111</option>
<option value="2">222</option>
</select>
<input name="price" type="text" size="8">