insted of using echo:
if ($_POST["MerchandisingExperience"] == "") {
echo ("No experience");
}
else {
echo ((isset($_POST["MerchandisingExperience"]))?$_POST["MerchandisingExperience"]:"");
}
you need to append to the $MailBody string:
if ($_POST["MerchandisingExperience"] == "") {
$MailBody = $MailBody . "No experience";
}
else {
$MailBody = $MailBody . ((isset($_POST["MerchandisingExperience"]))?$_POST["MerchandisingExperience"]:"");
}