为了避免许多if-else结构，让Javascript自动完成：
<select name="name" id="name"> <option value="a">a</option> <option value="b">b</option></select><script type="text/javascript"> document.getElementById('name').value = "<?php echo $_GET['name'];?>";</script><select name="location" id="location"> <option value="x">x</option> <option value="y">y</option></select><script type="text/javascript"> document.getElementById('location').value = "<?php echo $_GET['location'];?>";</script>
