URL Parameters

Can someone look at my code (below) which contains data fields from a sql datasource as some of my url parameters?
The problem i'm having is that my browsers only recognise the 1st part of the url - https://www.paypal.com/cgi-bin/webscr?cmd=_xclick&business=my_paypal_email&item_name= - and nothing after.
https://www.paypal.com/cgi-bin/webscr?cmd=_xclick&business=my_paypal_email&item_name=<%# Eval("Description") %>&amount=<%# Eval("PRICE") %>&undefined_quantity=1&currency_code=GBP
 
Can anyone see why?
Thanks
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