勾选大分类自动勾选子分类选项

[javascript]代码库

onclick="javascript:checknode(this);"

function checknode(obj)
  {
      var chk = $("input[type='checkbox']");
      var count = chk.length;
      var num = chk.index(obj);
      var level_top = level_bottom =  chk.eq(num).attr('level')
      for (var i=num; i>=0; i--)
      {
              var le = chk.eq(i).attr('level');
              if(eval(le) < eval(level_top)) 
              {
                  chk.eq(i).attr("checked",'checked');
                  var level_top = level_top-1;
              }
      }
      for (var j=num+1; j<count; j++)
      {
              var le = chk.eq(j).attr('level');
              if(chk.eq(num).attr("checked")=='checked') {
                  if(eval(le) > eval(level_bottom)) chk.eq(j).attr("checked",'checked');
                  else if(eval(le) == eval(level_bottom)) break;
              }
              else {
                  if(eval(le) > eval(level_bottom)) chk.eq(j).attr("checked",false);
                  else if(eval(le) == eval(level_bottom)) break;
              }
      }
  }

[代码运行效果截图]