I'm working on an iOS shopping app where users are shown a popup where they can choose to proceed to checkout as guest or login if they are registered. The design requires the popup to expand to show the password field if the user wants to login (otherwise only the email id field is shown so that he can proceed as guest). If users enter invalid email id or leave a field blank, the popup is required to expand further so that the users can be notified near the fields.
The only issue is, the design is such that this whole popup has the color, gradient and animation of UIAlertView, including the buttons. And as the normal UIAlertView can't be used to provide such extended functions, I designed it myself (as a view) and I'm presenting it modally with animations so that it looks like a UIAlertView has appeared
I just wanted to know whether this kind of imitation could lead to my app being rejected in the app store.