js二级下拉菜单怎么做

1、国家下拉框数据填充：<div class="form-group"争犸禀淫> <label class="col-sm-3 control-label">国家和地区<i class="required">*</i></label> <div class="col-sm-9"> <select id="country" class="col-md-12 validate" placeholder="请选择国家和地区"> </select> </div></div>

2、省份下拉框数据填充：<div class="form颍骈城茇-group"> <label class="col-sm-3 control-lab髫潋啜缅el">省份</label> <div class="col-sm-9"> <select id="state" class="col-md-12 validate" placeholder="请选择省份"> </select> </div></div>

3、js调用<script type="text/javascript"> getCountryForSpinner("ltCountry", countryID); getStateForSpinner("ltState", stateID, countryID);</script>