How do i add a Paypal Donation button to my SMF forum.

 

Here is the code:

<form target="_blank" action="https://www.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="cmd" value="_s-xclick">
<input type="hidden" name="hosted_button_id" value="1855079">
<input type="image" src="https://www.paypal.com/en_US/i/btn/btn_donateCC_LG.gif" border="0" name="submit" alt="">
<img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
</form>

 

When I add it this problem happens:

(go to the URL and click the 1st donate button)

http://l2eclipse.com/forum/index.php?topic=6.0

 

I cannot understand how to solve this...

I have this problem when I click the button:

 

Session verification failed. Please try logging out and back in again, and then try again.

 

Shall I have to register an account to your forum?

I have this problem when I click the button:

 

Session verification failed. Please try logging out and back in again, and then try again.

 

Shall I have to register an account to your forum?

Same problem, even registered

 

[EDIT]

2nd donate button works.