html: fieldset and legend markup
<fieldset>
<legend>Billing Affress</legend>
<label for="billAddress">Address</label><input type="text" id="billAddress" name="billAddress" />
<label for="billCity">City</label><input type="text" id="billCity" name="billCity" />
<label for="billProvince">Province</label><input type="text" id="billProvince" name="billProvince" />
<label for="billPC" >Postal Code</label><input type="text" id="billPC" name="billPC" />
</fieldset>