open the bindings panel, click the plus button and select URL Variable, name the new URL variable "report"
look at the address bar when you visit the details page, it will contain a url variable with the ID for the record being loaded, make note of the URL variable name. for example:
create the link on the details page, point it back to the same details page and include the report url variable, and include the original ID url variable:
<a href="details.php?id=<?php echo(isset($_GET['id'])?$_GET['id']:""); ?>&report=true">Report</a>
add the Universal Email behavior, for the trigger, click the lightning bolt icon and select the report URL binding.
for the Body, deselect the option to create a file to manage the email, and click the DW Edit button. In the page that opens, you can access the bindings panel to use the details page recordset bindings to populate the email body.