<div class="demo">
<form action="select1.php" method="get">
<select name="position" id="country_id" >
<option value="0">Disctrict : </option>
<option value="1">1. Remote Island</option>
<option value="2">2. Kwai Tsing</option>
<option value="3">3. NT North</option>
<option value="4">4. Sai Kung / Tseung Kwan O</option>
<option value="5">5. Shatin</option>
<option value="6">6. Tai Po</option>
<option value="7">7. Tsuen Wan</option>
<option value="8">8. Tuen Mun</option>
<option value="9">9. Yuen Long</option>
<option value="10">10. Kowloon City</option>
<option value="11">11. Kwun Tong</option>
<option value="12">12. Sham Shui Po</option>
<option value="13">13. Wong Tai Sin</option>
<option value="14">14. Yau Tsim Mong</option>
<option value="15">15. Central and Western</option>
<option value="16">16. HK Island East</option>
<option value="17">17. HK Island South</option>
<option value="18">18. Wan Chai</option>
</select>
</div>
</form>
<div class="demo">
<select name="position" id="country_id">
<option value="0">Project Type :</option>
<option value="1">1.Traffic Engineering</option>
<option value="2">2. Traffic Engineeering - GBP</option>
<option value="3">3. ic Engineering</option>
<option value="4">4. Traffic Study</option>
<option value="5">5. TTA</option>
<option value="6">6. Traffic Engine Lease</option>
<option value="7">7. Traffic Engineeering - GBP</option>
<option value="8">8. Traffic Forecasting</option>
</select>
------解决思路----------------------
先从数据库中select出你要的字段，然后一个for循环输出列表项
------解决思路----------------------
去看下三级联动
------解决思路----------------------
1个下拉菜单就传1个数据
2个下拉菜单就传2个数据
依次类推
php 是根据传入的数据筛选数据库的，与数据来源并无直接关系