DHTML stands for Dynamic HTML. The first thing that we need to clear about DHTML is that it is neither a language like HTML, JavaScript etc. nor a web standard. It is just a combination of HTML, JavaScript and CSS. It just uses these languages features to build dynamic web pages. DHTML is a feature of Netscape Communicator 4.0, and Microsoft Internet Explorer 4.0 and 5.0 and is entirely a "client-side" technology.  

Features of DHTML:

- Simplest feature is making the page dynamic.

- Can be used to create animations, games, applications, provide new ways of navigating through web sites.

- DHTML use low-bandwidth effect which enhance web page functionality.

- Dynamic building of web pages is simple as no plug-in is required.

- Facilitates the usage of events, methods and properties and code reuse. 

- The merchant submits a credit card transaction to the Payment Gateway on behalf of a customer via secure connection from a Web site, at retail, from a MOTO center or a wireless device. 

- Payment Gateway receives the secure transaction information and passes it via a secure connection to the Merchant Bank’s Processor. 

- The Merchant Bank’s Processor submits the transaction to the Credit Card Interchange (a network of financial entities that communicate to manage the processing, clearing, and settlement of credit card transactions). 

- The Credit Card Interchange routes the transaction to the customer’s Credit Card Issuer. 

- The Credit Card Issuer approves or declines the transaction based on the customer’s available funds and passes the transaction results, and if approved, the appropriate funds, back through the Credit Card Interchange. 

- The Credit Card Interchange relays the transaction results to the Merchant Bank’s Processor. 

- The Merchant Bank’s Processor relays the transaction results to Payment Gateway. 

- Payment Gateway stores the transaction results and sends them to the customer and/or the merchant. This communication process averages three seconds or less. 

- The Credit Card Interchange passes the appropriate funds for the transaction to the Merchant’s Bank, which then deposits funds into the merchant’s bank account. The funds are typically deposited into your primary bank account within two to four business days.

- B2B (Business-to-Business)   :

In B2B, companies transact with each other. This includes the companies selling their product to wholesalers, distributors, etc

- B2C (Business-to-Consumer) :

This is usually when average businesses transact with the customer. This is done through the shopping cart softwares and the amount involved in the transactions is usually low.

- C2B (Consumer-to-Business) :

In this, a consumer places the product on the net. The companies willing to buy this product bid for it. The comsumer can then decide, depending upon the bid, which company to sell it to. 

- C2C (Consumer-to-Consumer):

These kind of transactions are usually done at an individual level. Payments can be done with the help of online systems like PayPal.

The major benefits of Ecommerce are:

- Secure       : More secure than a cheque.

- Fast           : The transactions take not more than a few seconds

- Always on  : The purchases can be made 24/7

- Convenient:  Ease of purchasing

-Reduced cost price : Reduction of Marketing and Advertising Costs

=> When a consumer wants to buy a certain product, he go to the website and selects the product he wants to buy. 

=> Once the product is selected, the consumer transaction is moved to the online transaction server where he places an order. 

=> The informations is exchanged over a secure channel through a private gateway to a processing network. 

=> The networked banks accept or reject the transaction.

 All this happens in just a matter of seconds. E-commerce is a very secure due to the SSL (Secure Socket Layer) technology.

- Web servers can be infiltrated using the command shell by an attacker to read the HTML files that is getting transferred. 

- If the set-uid scripts are not proper and bad then the infiltration can happen by the attacker. 

- The processes are not given proper permissions so that the password can be changed by using the “passwd” command to change the password of the system.

- This also authenticates the user for accessing the system and the files on it containing the data. 

- The program that is used in the operating system doesn’t follow the principle of least privilege and lead to security issues.

Security features are very essential in the system as it provides an overall security of the system by applying the patches and the services that keeps the unwanted access away. 

The security features included are as follows:

- Use of algorithms in relation to, the security and the system to, solve the problem of the security. 

- Use of SSL or any encryption method to, protect the system from intrusion or any other attack. 

- Use of SSL in the SimpleWebServer that doesn’t provides the protection against the DoS attack and doesn’t allow the accessing to, be done using the /etc/shadow.

- The infinite file error can be solved when the data will be read continuously from the file. 

- The error can be solved by using the keys that provide only the resources that are required. 

- The following program is as follows:

osw.write ("HTTP/1.0 200 OK\n\n"); 

while (c != -1) { 

sb.append((char)c); 

c = fr.read(); 

} 

osw.write (sb.toString()); 

- This converts the requested file in such a way that if the file exists it shows the messages as ok otherwise it shows an error.

- Limited file access is to be given to the file to remove the error from the infinite file type.