<input type="checkbox" name="slabed" value="1"> <b>Slabed</b> <span><b>By</b><input type="text" name="slabedby"></span>
some details: Dynamic form
within a PHP script
could have more than one field hence the bracket  for making array of the form submission.
Has to work in all major Browsers
The input field inside the tag might turn out to be a dropdown instead, not sure yet.