Sets the Custom Payment Page Style for payment pages associated with this button/link. The value of page_style is the same as the Page Style Name you chose when adding or editing the page style. You can add and edit Custom Payment Page Styles from the Profile section of the My Account tab. If you would like the button/link to always reference the style you make Primary, set this variable equal to "primary." If you would like the button/link to reference the default PayPal page style, set this variable equal to "paypal." The page_style variable has a maximum length of 30 characters. Valid character set is alphanumeric ASCII lower 7-bit characters only, plus underscore. It cannot include spaces.