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In generic terms accessibility can be described as the process wherein regardless of the circumstances and situations the access has to be provided. While in terms of World Wide Web accessibility can be best defined as the measure of how easy it would be access, read and understand the website’s content. The whole concept o accessibility becomes a little complicated mainly due to the fact that website cannot be merely compared to a living document which can be easily published on the net and thereby be easily interpreted in different ways by various browsers on several platforms.
There are different ways to experience a web page which primarily include an indexing browser or a speech browser. W3C has its own set of specifications or guidelines in terms of accessibility which is one of the major concerns of the markup language. There is a complete association of each of the guidelines with one or more checkpoints which very clearly give a detailed description of different ways of application of a guideline to any particular feature of a web page.
The first and the foremost guideline can be listed as providing equivalent alternatives especially to the visual and the auditory content. To explain this we take a simple example, if there is a certain graphical arrow on the web page which points to the left side of the screen just to signify that by clicking on the arrow the user can go back. According to the W3C guidelines, it is mandatory for any web site to provide with the alternative text to this graphical image which would read something like Go Back TO The Previous Page.
Secondly, don’t rely for any kind of description on colors alone or in other words use of colors as a visual cue should be avoided as far as possible. This is very important for the color blind people. And if at all you have to use them there should be a high level of contrast in the background and the text. Next is to make proper use of the style sheets and the markups. It will allow the users to distinguish properly between the content, presentation and structure and therefore easily navigate through the web page.
If you are making use of the natural language, it is very important that you clarify its usage. This can be achieved by using the LANG tag in the head of the document and setting its value as the ISO standards which would be a two letter abbreviation for each language. Only those tables should be created which transform gracefully. Tables should be used to hold the tabular data and not just for achieving a particular design or feature.
Always ensure that the web pages which are using new technologies are able to transform gracefully. This means that when you have finished created a web page and incorporated all the latest technologies, it is very important that your web page can still be viewed by older pages as well. If there are any kinds of time sensitive content changes such as blinking, moving or scrolling the user should be able to control them in terms of pausing or stopping. Always ensure that the embedded user interfaces are based on the principles of accessibility such as self voicing, keyboard operability and device independent access to functionality etc.
Always provide with consistent and clear navigation mechanisms to the users. For the older browsers and the assistive technologies to operate correctly, make use of interim accessibility solutions. There should be a proper design that should be given on your web page for device independency. Always ensure that all your documents are very clear and at the same time quite simple. And finally and the most obvious ones make use of all the technologies and the guidelines listed by W3C.
Therefore, the guidelines stated by W3C will help in making your web site highly accessible for all including the people with some kind of disabilities.

So far we have discussed about various types of tags and objects of HTML documents but haven’t come across any methodology which can control the data embedded in them. In a simple HTML document the web browser cannot separate data from the content and thus the user can’t manage and manipulate it. In order to solve this issue the concept of Data Binding was introduced. Via data binding one can associate the data of a database with the HTML pages. Once the web page is downloaded and opened by the web browser the data associated with that page can be differentiated from the any other content and the user has full control over it. Data binding offers a vast array of new methods and properties for HTML tags which can be used to associate a database with the web page.

Data binding involves three basic steps:

1) Adding a data source to the HTML document
2) Binding HTML elements to the data source
3) Developing scripts to control the bonded database table

Adding the Data Source object to the web page

The first and foremost step towards data binding is to identify the data source and add it to the web page. In order to accomplish this The Data Source Objects (DSO) are used. DSOs are provided by Microsoft and are used for supplying data to the web browser. In order to do this, the DSO identifies the data source through various methods such as SQL queries, URLs etc.

Apart from this DSOs are also used to manipulate the data. It is used to give the user complete control over the data. DSO offers a large number of properties, events and methods in order to accomplish this.

The Microsoft’s Internet Explorer comes with two built-in DSOs. The first one is the Advanced Data connector (ADC) and the other one is the Tabular Data Control (TDC). ADC is meant to access the database via server and ODBC (Open Database Connectivity) components. TDC is used to access tabular data stores in the form of comma-delimited text files. Without the DSO no web page can get and access the data.

Binding HTML elements to the data source

It is very crucial to associate the HTML page to the Data source Object. With the help of DATASRC and DATAFLD attributes, the data can be bonded with the HTML elements. The DATASRC refers to the Data Source Object (DSO) and the DATAFLD refers to a specific column of the database. Both of them have to be defined in the HTML code in order to associate a database table with the web page.

Scripting of Data Source Objects

Once the data source has been identified and associated with the HTML document, the final step is to create a script for that which will allow the user to control the data in a particular manner. Without scripting the user cannot manipulate the data. Scripting is done by using different types of properties and methods of Data Source Object.