Add field at page render

I added a extra field to page added and get data from another page using GET requestPage rendering
input type=“text” data-table=“ITEM_TAKEN” data-field=“x_CODE” name=“x_CODE” id=“x_CODE” size=“30” maxlength=“8” placeholder=“CODE” value=<?php echo $CODE; ?> class="form-control"When submiting the page how to get the value of my custom field in row_inserting page

Post(‘x_CODE’) should hold the value