hi friends, I have some queries about E-commerce sites.Plz help 1. If i have an E-commerce site and i sell products online how can i be sure that the credit card no. given by the customer is valid and has not expired. 2.How can i be sure that the credit card no. has not been tampered with midway before coming to the site. 3.If i want to use my own server can i rely on mysql database server and php scripting, both performance and security wise. 4.If Mysql and php are best then why arent big e-commerce sites using it. 5.Do u know what sites like Bazee.com, rediff.com,yahoo.com etc. use. Plz Answer.Thnx in advance.