Writing Problems

Dear List -

I can't figure this one out.....

1] Straighten out ownership

ethan@meow:/var/www$ rm receipt.txt
ethan@meow:/var/www$ touch receipt.txt
ethan@meow:/var/www$ ls -l receipt.txt
-rw-r--r-- 1 ethan ethan 0 Aug 26 19:31 receipt.txt
ethan@meow:/var/www$ chmod 766 receipt.txt
ethan@meow:/var/www$ ls -l receipt.txt
-rwxrw-rw- 1 ethan ethan 0 Aug 26 19:31 receipt.txt

This is what we want

2] Now program code ....

ini_set('display_startup_errors', 'on');
error_reporting(E_ALL | E_NOTICE);
ini_set('display_errors','1');
error_reporting(1);


$fh2 = fopen("/var/www/receipt.txt", "a+");

want this file to be like a cash register receipt.  I can truncate this 
file for each execution of the program; ie, when all the purchases are 
finished.

$sql3 = "select quant, orderpt,  ordrpt_flag, manuf, item, stock, price, 
tax_flag  from Inventory where UPC = $upc";
$result3 = mysqli_query($cxn, $sql3);
$row3 = mysqli_fetch_row($result3);

print_r($row3 ); //gives correct results.

$numbyt=fprintf($fh2, "%s %s %.2f %s\n",$row3[3] , $row3[4], $row3[6], 
$row3[7]);

echo "<br />numbyt fh2 $numbyt<br />";	//result is 0

No errors.

What is wrong??

TIA

Ethan