<input name="field_null[<?php echo $columnNumber; ?>]"
id="field_<?php echo $columnNumber; ?>_<?php echo ($ci - $ci_offset); ?>"
<?php if (! empty($columnMeta['Null']) && $columnMeta['Null'] != 'NO' && $columnMeta['Null'] != 'NOT NULL'): ?>
checked="checked"
<?php endif; ?>
type="checkbox"
value="NULL"
class="allow_null"/>