Paypal不接受'汇款'我通过了

第一次在这里，我有一个问题，我在php写的网站。我试图让贝宝接受一个单一的支付传递它的值如下。我使用了他们的Create Button工具，并添加了一些额外的字段。$idTeacher字段通过paypal完美，但$MaxHourlyRate没有(他们都存在，但我可以回显他们)。如有任何建议，我将不胜感激:

echo "<table border='1' cellpadding='0' cellspacing='1'>";
echo "<tr><td>Passed #</td><td>#Contract</td><td>Language</td><td>Language Level</td><td>PLZ</td><td>Frequency</td><td>Max Hourly Rate</td><td>Reserve Contract</td></tr>";
while($row = mysql_fetch_array($pendingcontractsql)){
$idContract = $row['idContract'];
$Language = $row['Language'];
$LanguageLevel = $row['LanguageLevel'];
$PLZ = $row['PLZ'];
$Frequency = $row['Frequency'];
$MaxHourlyRate = $row['MaxHourlyRate'];

echo "<tr>";
echo "<td>$MaxHourlyRate</td><td>".$row['idContract']."<td>".$row['Language']."</td><td>".$row['LanguageLevel']."</td><td>".$row['PLZ']."</td><td>".$row['Frequency']."</td><td align='right'>".$row['MaxHourlyRate']."CHF</td><td align='center'>
<form action='https://www.paypal.com/cgi-bin/webscr' method='post'>
<input type='hidden' name='cmd' value='_s-xclick'>
<input type='hidden' name='business' value='brettstirling@gmail.com'>
<input type='hidden' name='quantity' value='1'>
<input type='hidden' name='no_note' value='1'>
<input type='hidden' name='no_shipping' value='1'>
<input type='hidden' name='currency_code' value='CHF'>
<input type='hidden' name='item_name' value='Payment for Contract #".$idContract."'>
<input type='hidden' name='item_number' value='$idContract'>
<input type='hidden' name='amount' value='$MaxHourlyRate'>
<input type='hidden' name='discount_rate' value='50'>
<input type='hidden' name='notify_url' value='http://www.findateacher.ch/paypalipn.php'>
<input type='hidden' name='return' value='http://www.findateacher.ch/availablecontract.php'>
<input type='hidden' name='rm' value='2'>
<input type='hidden' name='cbt' value='Return to Find A Teacher'>
<input type='hidden' name='hosted_button_id' value='LRABWTJVH7N36'>
<input type='submit' border='0' name='submit' value='Reserve Contract'>
</form>
</td>";
echo "</tr>";
}
echo "</table>";

提前感谢，布雷特