I assume you mean the Logged In As Post Owner rule?
in this rule you are comparing a session to POST value.
a post value is only availbal when a foprm is being posted.
if a form is not used to load this page that passes in the customerid form element, there is no way this rule will be able to work.
your events recordset should return the customerid column, instead of using the security assist access rules for this, use the Show region utility. on the server behaviors panel, click the plus button and select WebAssist -> Utilities -> Show Region.
for the IF, select the customerid Session variable.
for the comparison, use Equals, and the value, select the customerid column from the WADADetails recordset.