JS简单设置下拉选择框默认值的方法

//根据下拉对象默认选中后台对应的记录
function setSelectOption(objSelect, targetValue){
     if(objSelect){
      var options = objSelect.options;
      if(options){
       var len = options.length;
       for(var i=0;i<len;i++){
        if(options[i].value == targetValue){
         options[i].defaultSelected = true;
         options[i].selected = true;
         return true;
        }
       }
      } else {
       alert('missing element(s)!');
      }
    } else {
      alert('missing element(s)!');
    }
}