Dynamically turning undefined index using asset()

I'm writing a generic function that will take a large number of fields from $_POST and build an SQL insert into a table. In this case, I have a number of Undefined indexes and from reading other posts on SO, I am using a ternary to test if the variable exists. This works perfectly when I use it in interactive php, especially since there are no $_POST variables defined.

But when I use it in my form, I seem to get a extra quote and a few returns but I cannot see where they are coming from. I've beaten about this in different ways but am hoping someone can help me see what I'm not seeing.

  function SaveDonation($form)
  { try 
    {
    $querystr = "INSERT INTO GeneralDonations(
  donationForm, firstName, startYear)" . "VALUES(" . "'" . $form 
  ."', " .
    ((!isset($_POST['firstName'])) ? "'', " : ("'" . mysql_real_escape_string($_POST['firstName'])."', ")) .
    ((isset($_POST['startDate'])) ? ("'" . mysql_real_escape_string($_POST['startDate'])."' ") : "'' ") 
.")";

echo "query = " . $querystr;

$donation = $this->db->insertRow($querystr);
$result = true;

}
catch(MysqlException $e)
{
  $result = false;
  $this->errorMsg = $e->getMessage();
}
return $result;
}

The startDate is the undefined index value. This is the browser output. Pls help me see what's different here?

 query = INSERT INTO GeneralDonations( donationForm, firstName, startYear)VALUES('buy-a-foot', 's', '
 \r\n\r\n