Fundamentals of DHTML for beginners

Once a web server courses a web page & drives it to the computer requesting it (known the 'Client' computer) it can’t get any more data from the server unless a new request is made. So to move around this drawback we use DHTML which is combining HTML and a scripting language that runs on the Client's browser to bring unique effects to otherwise static pages. The scripting language that we will be using is JavaScript as most browsers support it. The scripting language can be used to modify HTML data shown on the current page by controlling the properties for the HTML tags involved. The most important examples of DHTML are as follows:
• Appling Layers: All the data to always be displayed is loaded into the offered pages in HTML format but is hidden by using the visibility property of HTML layer elements like LAYER, DIV, etc. Now when an event like Mouse Over arises a JavaScript function is called to show the layer. The layer is then concealed on Mouse Out event.
• Appling Image Rollovers & Swaps: If you have some knowledge of website designing then you should know that when creating Image rollovers or image swaps you usually take some script & consist of it to the content of your HTML pages. If you look carefully at the HTML code for the images you will discover that they call functions on Mouse Over and Mouse Out events.
• Appling Dynamic Forms : While surfing you must have seen how some forms appear to have special functions like
1. Validation of fields
2. Text box character limits
3. Dynamic displayed lists depending on your selection
4. Redirection to additional pages
5. Manipulating your keyboard input or disabling some keys or browser buttons, etc. Well all this is done through calling some corresponding script functions.
• Appling Cascading Style Sheets (CSS): Yes, you might be astonished to recognize that CSS is part of DHTML. A CSS file is just a JavaScript file with the extension .css which is essential for it to be recognized by the server and tools like Macromedia's Dreamweaver to contain styles.