PayPal IPN - minimum fields required for a purchase button?

I am using "buy it now" PayPal buttons but I DO NOT want to use the previously saved buttons on my PayPal account, I want to create a custom form that has a submit button. However, I need to know which f开发者_JS百科ields are the minimum required ones for a form. I thought it would be something like this

<input type="hidden" name="cmd" value="_s-xclick" >
<input type="hidden" name="business" value="me@myemail.com" >
<input type="hidden" name="item_name" value="some item name" >
<input type="hidden" name="item_number" value="some item number" >
<input type="hidden" name="amount" value="10.00" >

But this keeps on kicking back as an unpecified error on PP. Any thoughts?

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The following link has a minimal example: https://www.paypal.com/cgi-bin/webscr?cmd=_pdn_xclick_techview_outside . The most important parts are making sure the action is correct and the cmd field is correct. (I'm not familiar with _s-xclick as a command – I always use _xclick myself – but my knowledge in the area is admittedly a bit dated.)

For more tips on making the form just right, I recommend poking around on the PayPal Developer network: https://www.x.com/index.jspa

Also, please note: PayPal IPN is a feature that does callback posts from PayPal to you, the merchant, after a purchase is made, and doesn't quite seem to be what you're working with here, which is the button's form posted from the user's browser to PayPal. This form submission in a buy-now button is just considered part of the buy-now button feature.