That isn't the same as the code I provided.... it should be:
<button type="button" onclick="document.location.href='Enquiries/boatenquiry_insert.php?RecNo=<?php echo($WADAboats->getColumnVal("RecNo")); ?> >'">click here</button>
You have:
<button type="button" onclick="document.location.href='Enquiries/boatenquiry_insert.php?RecNo=
<?php echo($WADAboats->getColumnVal("RecNo")); >'">click here</button>
Make sure you copy from the forum post on the web and not your email. Email clients can change the text and make it unusable.