JS实现：选中父checkbox时子checkbox同时被选中

 html中checkbox定义:

<input type="checkbox" value="@@@list_category_id@@@" name="DEL_CATEGORY_ID" onclick="doChoiceCheckbox()">

JS:从ary[]中取值判断

function doChoiceCheckbox()...{
        if (ary.length == 0)...{
        return false;
    }
    var choiceCategoryId = "";
    if (document.ftcartForm.DEL_CATEGORY_ID.type=="checkbox")...{
        if (document.ftcartForm.DEL_CATEGORY_ID.checked)...{
            choiceCategoryId += document.ftcartForm.DEL_CATEGORY_ID.value;
        }
    }else...{
        for (var i=0;i<document.ftcartForm.DEL_CATEGORY_ID.length;i++)...{
            if (document.ftcartForm.DEL_CATEGORY_ID[i].checked)...{
                choiceCategoryId += document.ftcartForm.DEL_CATEGORY_ID[i].value;
            }
        }
    }
        if(!choiceCategoryId=="")...{           
               for(var x=0;x<ary.length;x++)...{
                 if(choiceCategoryId==ary[x].id&&ary[x].parentCategoryId=='-1')...{
                     for(var y=0;y<ary.length;y++)...{
                         if(ary[y].parentCategoryId==ary[x].id)...{
                             document.getElementsByName("DEL_CATEGORY_ID")[y].checked = true;   
                         }
                     }
                 }
               }
        }
}