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AJAX is about updating parts of a web page, without reloading the whole page. What You Should Already Know Before you continue you should have a basic understanding of the following: HTML / XHTML CSS JavaScript / DOM If you want to study these subjects first, find the tutorials on our Home page. What is AJAX? [...]
AJAX = Asynchronous JavaScript and XML. AJAX is not a new programming language, but a new way to use existing standards. AJAX is the art of exchanging data with a server, and update parts of a web page – without reloading the whole page. AJAX Example Let AJAX change this text Change Content Try [...]
Events are actions that can be detected by JavaScript. Acting to an Event The example below displays the date when a button is clicked: Example <html><head> <script type=”text/javascript”> function displayDate() { document.getElementById(“demo”).innerHTML=Date(); } </script> </head> <body> <h1>My First Web Page</h1> <p id=”demo”></p> <button type=”button” onclick=”displayDate()”>Display Date</button> </body> </html> Try it yourself » Events By [...]
The for…in statement loops through the properties of an object. Syntax for (variable in object) { code to be executed } Note: The code in the body of the for…in loop is executed once for each property. Example Looping through the properties of an object: Example var person={fname:”John”,lname:”Doe”,age:25}; for (x in person) { document.write(person[x] + ” [...]
= is used to assign values. + is used to add values. The assignment operator = is used to assign values to JavaScript variables. The arithmetic operator + is used to add values together. y=5; z=2; x=y+z; The value of x, after the execution of the statements above, is 7. JavaScript Arithmetic Operators Arithmetic operators are [...]
JavaScript has three kind of popup boxes: Alert box, Confirm box, and Prompt box. Alert Box An alert box is often used if you want to make sure information comes through to the user. When an alert box pops up, the user will have to click “OK” to proceed. Syntax alert(“sometext”); Example <html> <head> <script [...]
A function will be executed by an event or by a call to the function. JavaScript Functions To keep the browser from executing a script when the page loads, you can put your script into a function. A function contains code that will be executed by an event or by a call to the function. [...]
What is a Cookie? A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user’s computer. Each time the same computer requests a page with a browser, it will send the cookie too. With ASP, you can both create and retrieve cookie values. How [...]
User Input The Request object can be used to retrieve user information from forms. Example HTML form <form method=”get” action=”simpleform.asp”> First Name: <input type=”text” name=”fname” /><br /> Last Name: <input type=”text” name=”lname” /><br /><br /> <input type=”submit” value=”Submit” /> </form> User input can be retrieved with the Request.QueryString or Request.Form command. Request.QueryString The Request.QueryString command [...]
In ASP you can call a JavaScript procedure from a VBScript and vice versa. Procedures The ASP source code can contain procedures and functions: Example <html> <head> <% sub vbproc(num1,num2) response.write(num1*num2) end sub %> </head> <body> <p>Result: <%call vbproc(3,4)%></p> </body> </html> Insert the <%@ language=”language” %> line above the <html> tag to write the procedure/function [...]