Log JavaScript errors server-side with this simple PHP script

logerrors.php

<?php
if (isset($_GET) && count($_GET) > 0) {
    
    function logErrors($fh, array $fields, $delimiter = ',', $enclosure = '"', $mysql_null = false) {
        
        if (is_writable($fh)) {
            
            $filename = $fh;
            
            if (!$handle = fopen($fh, 'a+')) {
                echo "Cannot open file ($filename)";
                exit;
            }
            
            $objDateTime = new DateTime('NOW');
            
            if (fwrite($handle, 'date/time' . ': ' . $objDateTime->format(DateTime::RFC822) . "\n") === FALSE) {
                echo "Cannot write to file ($filename)";
                exit;
            }
            
            foreach ($_GET as $key => $value) {
                
                if (fwrite($handle, $key . ': ' . stripslashes($value) . "\n") === FALSE) {
                    echo "Cannot write to file ($filename)";
                    exit;
                }
                
            }
            
            if (fwrite($handle, "\n") === FALSE) {
                echo "Cannot write to file ($filename)";
                exit;
            }
            
            fclose($handle);
            
        } else {
            echo "The file $filename is not writable";
        }
    }
    
    logErrors('elevaate-errors.txt', $_GET);
    
}