click only table header titel

In my table if I click table header data will be sorted.There is check box in that header when i click on header title that check box also clicking.I want only working the sort when i click on header title.

my table

This is the table header.

 <thead>
                                        <tr>
                                            <?php if ($folder_id && $sub_folders) { ?><th width="2%"><input type="checkbox" id="selectall" class="selected_check"></th><?php } ?>
                                            <?php if (isset($sub_folders)) { ?><?php } else { ?><th width="5%"></th><?php } ?>
                                            <th width="5%"></th>
                                            <th class="vf-icon"></th>
                                            <th ><?php if (isset($sub_folders)) { ?><a href="<?php echo base_url('files/browse') . "/" . $folder_id . "/title"; ?>" style="cursor: pointer;"><?php } else { ?><a href="<?php echo base_url('files/browse') . "/0/title"; ?>" style="cursor: pointer;"><?php } ?>Title</a></th>
                                            <th width="20%" class="text-center"><?php if (isset($sub_folders)) { ?><a href="<?php echo base_url('files/browse') . "/" . $folder_id."/size"; ?>" style="cursor: pointer;"><?php } else { ?><a href="<?php echo base_url('files/browse') . "/0/size"; ?>" style="cursor: pointer;"><?php } ?>Size</a></th>
                                            <th width="20%" class="text-center"><?php if (isset($sub_folders)) { ?><a href="<?php echo base_url('files/browse') . "/" . $folder_id."/last_updated"; ?>" style="cursor: pointer;"><?php } else { ?><a href="<?php echo base_url('files/browse') . "/0/last_updated"; ?>" style="cursor: pointer;"><?php } ?>Last Updated</a></th>
                                            <th width="20%" class="text-center"><?php if (isset($sub_folders)) { ?><a href="<?php echo base_url('files/browse') . "/" . $folder_id."/created_by"; ?>" style="cursor: pointer;"><?php } else { ?><a href="<?php echo base_url('files/browse') . "/0/created_by"; ?>" style="cursor: pointer;"><?php } ?>Created By</a></th>
                                            <th></th>

                                        </tr>

                                    </thead>