if($tablename=='trips')
{
	// insert any blank dates
	$datemax = mysql_result(mysql_query("select max(date) from trips",$con),0);
	$dategiven = $_POST['date'];
	$period = new DatePeriod(
		 new DateTime($datemax),
		 new DateInterval('P1D'),
		 new DateTime($dategiven)
	);
	foreach ($period as $date) {
	  if($date->format('Y-m-d') != $dategiven AND $date->format('Y-m-d') != $datemax) {
	  mysql_query("INSERT into trips (date, kms) VALUES (\"".$date->format('Y-m-d')."\",0)",$con);
	  };
	}
}
// insert the form data

mysql_query('DELETE FROM '.$tablename.' WHERE date = "'.$_POST['date'].'"',$con);  // delete any existing data on that date to prevent multiple entries

$col_name = ""; $newvalue = "";
foreach ($_POST as $key=>$value) {		// this creates the list for the sql insert string
	if($key!="formID")
		{
		$col_name .= $key.",";
		if ($value != '')
			{
			$newvalue .= chr(39).$value.chr(39).",";
			}
		else
			{
			$newvalue .="NULL,";
			}
		}
	}


$col_name = substr($col_name,0,-1); $newvalue = substr($newvalue,0,-1);   // removes the last comma

$sql = "INSERT INTO $tablename ($col_name) VALUES ($newvalue)";

	if (!mysql_query($sql,$con))
		 {
		   die('Error: ' . mysql_error());
		 }