I need guidelines to integrate paypal payment gatway. Here is my requirement
1.User would click on pay button on my website to open paypal payment gateway page.
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2.User may not have a paypal account. He/she need to enter details of credit card only. (It should not force user to login)
AFAIK this is not possible. User should have paypal account and one of the main advantage of using paypal is that users need not reveal the credit card details.
3.User will enter what amount he want to pay?
Similar to Donations button from paypal
4.I do not need any response or confirmation from gateway. I would see details of transaction in my email
What email??? If you dont need the result then how will you know that the payment was successful or not???
What you are trying to do above is not possible. If You are using other paid payment gateway providers then you will be able to solve issue 2. Other than I dont think what you ask is possible.