lecture 9: CGI

Most commercial sites that use forms do so in a fully interactive way, however. In other words, the information submitted on the form is then used to create a page, the content of which depends on the submitted information. A close-to-home example of this comes with the ACOM bulletin board system. When you Submit the form (which in this case is just a <textarea> tag), a page comes up straight away which displays the information you submitted (as well as any previous messages in that thread). More commercial examples of this would be e-commerce sites, or Google.

Dynamic web content like this cannot be created using HTML alone. An alphabet soup of acronyms comes into play here, with technologies such as ASP (Active Server Pages), SQL (Structured Query Language) and - the one that matters most here - CGI (Common Gateway Interface).

The links in the previous paragraph all take you to free and good-quality tutorials on these topics. But there are further considerations to bear in mind. First, you need to have your site hosted on a server which can cope with these advanced technologies. You will need to check with your ISP (Internet Service Provider) about what support they offer. More significantly, you also need an understanding of web security. CGI can potentially be used in malicious ways.

There are plenty of sources of further advice here - books, as well as tutorials - see the online teaching materials for more details.