How can i create online payment website?

follow the steps:-

(i) purchase the payment gateway from any desired company

(ii) integrate the given code in your application

receiving payments online is not free service. you have to buy the gateway. gateway company will provide you the sample code, api etc.

Go over the links that Jitendra added, depending on the size of the company you are working for the finance department usually takes care of setting up the merchant account. If you are building a site for yourself than it is something you must do. There are companies like http://www.smartpaymentsolutions.com/developers/ that exposes are service for processing credit card and check payments. It is usually easy to write a wrapper for the service and on top of your credentials they will add valid ip addresses that can post to the service. Like smartpayment there are many other solutions out there and they are pretty good about giving you all the requirements for getting started. A popular approach for starting merchant sites is to go with paypal https://www.x.com/index.jspa.

Hi,
Go through these links:

http://www.businesslink.gov.uk/bdotg/action/detail?itemId=1075393702&type=CASE+STUDIES

http://banking.about.com/od/bankonline/f/setupbillpay.htm