Paypal Pay button generates GENERIC_ERROR

[Apipak]

Hi,

My Paypal Pay button doesn't work. The result is :

We're sorry, things don't appear to be working at the moment. Please try again later.

https://www.paypal.com/webapps/shoppingcart/error?flowlogging_id=0abaaa039a044&code=GENERIC_ERROR&mf...

Impossible to find what's wrong.

My paypal account has beed completed with bank account and card approved.

Block non-encrypted website payment is off in website preferences

here is the code (Personal informations have been replaced, like my_merchant_id or mywebsite)

I try to pay 1 Euro

<div align = "center"> <form action="https://www.paypal.com/cgi-bin/webscr" method="post" target="_top">

<input type="image" src="https://www.paypalobjects.com/fr_FR/i/btn/btn_paynowCC_LG.gif" border="0" name="submit" title="PayPal - The safer, easier way to pay online!" alt="Pay Now" />

<img alt="" border="0" src="https://www.paypal.com/fr_FR/i/scr/pixel.gif" width="1" height="1" />

<input type="hidden" name="charset" value="utf-8" />

<input type="hidden" name="no_shipping" value="2" />

<input type="hidden" name="amount" value="1.00" />

<input type="hidden" name="business" value="my_merchant_id" />

<input type="hidden" name="no_note" value="0" />

<input type="hidden" name="cancel_return" value="http://www.mywebsite.fr" />

<input type="hidden" name="item_name" value=<?php echo $commandid; ?>/>

<input type="hidden" name="button_subtype" value="services" />

<input type="hidden" name="cmd" value="_xclick" />

<input type="hidden" name="bn" value="my_merchant_id:PP-BuyNowBF_S" />

<input type="hidden" name="currency_code" value="EUR" />

<input type="hidden" name="return" value="http://www.mywebsite.fr" />

<input type="hidden" name="country" value="FR" />

<input type="hidden" name="first_name" value=<?php echo $fact_prenom; ?> />

<input type="hidden" name="last_name" value=<?php echo $fact_nom; ?> />

<input type="hidden" name="address1" value=<?php echo $fact_adresse1; ?> />

<input type="hidden" name="address2" value=<?php echo $fact_adresse2; ?> />

<input type="hidden" name="zip" value=<?php echo $fact_codepostal; ?> />

<input type="hidden" name="city" value=<?php echo $fact_ville; ?> />

<input type="hidden" name="night_phone_a" value=33&night_phone_b=<?php echo $telephone; ?> />

<input type="hidden" name="email" value=<?php echo $email; ?> />

</form>

</div>  

Any help is welcome

Apipak