Change this:
<?php
@session_start();
if ("" === "") {
$_SESSION["EDITeventID"] = "".((isset($_POST["eID"]))?$_POST["eID"]:"") ."";
}
?>
to this:
<?php
@session_start();
if (isset($_POST["eID"])) {
$_SESSION["EDITeventID"] = "".((isset($_POST["eID"]))?$_POST["eID"]:"") ."";
}
?>