Is there something syntactically wrong with my php code? On submission the page goes blank

Question

I have checked each part of this block countless times and can't seem to find why my request goes straight to a blank page.

Directly from the database to show spellings are right, where dataID is auto incrementing primary key and checkID and checkAssoc are a unique key together:

SELECT  `dataID` ,  `checkID` ,  `checkAssoc` ,  `completed_date` ,  `time_start` ,  `time_end` ,  `esig` ,  `pass_fail` 
FROM  `dTraineeCheckListData` 
LIMIT 0 , 30

<?php

if (isset($_POST['process'])) {

    if(isset($_POST['1startTime']) AND isset($_POST['1endTime']) AND isset($_POST['1signature'])) {
        $sql = "INSERT INTO `dTraineeCheckListData` (`checkID`, `checkAssoc`, `completed_date`, `time_start`, `time_end`, `esig`, `pass_fail`) VALUES (?, ?, ?, ?, ?, ?, ?) 
        ON DUPLICATE KEY UPDATE `completed_date`=VALUES(`completed_date`), `time_start`=VALUES(`time_start`), `time_end`=VALUES(`time_end`), `esig`=VALUES(`esig`), `pass_fail`=VALUES(`pass_fail`)";
        $poststmnt = $db_transpo->prepare($sql);
        $poststmnt->bind_param('iiiiiii',$_POST['trainee_id'], 1, NULL, $_POST['1startTime'],$_POST['1endTime'],$_POST['1signature'], NULL);

        if ($poststmnt->execute()) {
            echo '<div class="alertText">Data Update Successful.</div>';
        } else {
            echo '<div class="errorText">Some error occured in posting your data update, make sure all fields were filled out for the section.</div>';
            printf("Error: %s.\n", $poststmnt->error);
        }

        $poststmnt->close();
    }

}

Answer 1

bind_param is pass by variable. I added in the below code and it worked.

        $traineeCheckNumber = 1;
        $traineeCheckDate = NULL;
        $traineeCheckPassFail = NULL;
        $poststmnt->bind_param('iiiiiii',$_POST['trainee_id'], $traineeCheckNumber, $traineeCheckDate, $_POST['1startTime'],$_POST['1endTime'],$_POST['1signature'], $traineeCheckPassFail);

Answer 2

Add this line at the top of your script to see errors:

ini_set('error_reporting', -1);
ini_set('display_errors', 'on');