function setposition($table = null, $id = null, $field = null, $value = null)
    {
        if (IS_POST) {
            $position = I('position');
            $postr = implode(',', $position);
            $result = M($table)->where($table . '_id=' . $id)->save(array($field => $postr));
            if (0 < $result) {
                $this->success(array(status_to_text($postr, $table, $field), $postr));
            }
        } else {
            $str = '<form id="positionform" method="post" action="' . U('setposition') . '">
				  <input type="hidden" name="table" value="' . $table . '" />
				  <input type="hidden" name="id" value="' . $id . '" />
				  <input type="hidden" name="field" value="' . $field . '" />
				  ' . status_to_text($value, $table, $field, true) . '
				  </form>';
            $this->success($str);
        }
    }
    function setposition($table = null, $id = null, $field = null, $value = null)
    {
        if (IS_POST) {
            $position = I('position');
            $postr = implode(',', $position);
            $result = M($table)->where($table . '_id=' . $id)->save(array($field => $postr));
            if (0 < $result) {
                $this->success(array(status_to_text($postr, $table, $field), $postr));
            }
        } else {
            $url = U('setposition');
            $stext = status_to_text($value, $table, $field, true);
            $str = <<<eot
<form id="positionform" class="positionfield" method="post" action="{$url}">
<input type="hidden" name="table" value="{$table}" />
<input type="hidden" name="id" value="{$id}" />
<input type="hidden" name="field" value="{$field}" />
{$stext}
\t<a href="javascript:;" onClick=""  style="display:none;">添加</a>
</form>'
eot;
            $this->success($str);
        }
    }