#6
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AJAX XMLHttpRequest
The XMLHttpRequest object makes AJAX possible.
The XMLHttpRequest The XMLHttpRequest object is the key to AJAX. It has been available ever since Internet Explorer 5.5 was released in July 2000, but not fully discovered before people started to talk about AJAX and Web 2.0 in 2005. Creating An XMLHttpRequest Object Different browsers use different methods to create an XMLHttpRequest object. Internet Explorer uses an ActiveXObject. Other browsers use a built in JavaScript object called XMLHttpRequest. Here is the simplest code you can use to overcome this problem: |
#7
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var XMLHttp=null;
if (window.XMLHttpRequest) { XMLHttp=new XMLHttpRequest(); } else if (window.ActiveXObject) { XMLHttp=new ActiveXObject("Microsoft.XMLHTTP"); } Example above explained:
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#8
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A Better Example?
Some programmers will prefer to use the newest and fastest version of the XMLHttpRequest object. The example below tries to load Microsoft's latest version "Msxml2.XMLHTTP", available in Internet Explorer 6, before it falls back to "Microsoft.XMLHTTP", available in Internet Explorer 5.5 and later. function GetXmlHttpObject() { var xmlHttp=null; try { // Firefox, Opera 8.0+, Safari xmlHttp=new XMLHttpRequest(); } catch (e) { // Internet Explorer try { xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); } } return xmlHttp; } Example above explained:
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#9
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PHP and AJAX Suggest
AJAX Suggest
In the AJAX example below we will demonstrate how a web page can communicate with a web server online as a user enters data into a web form. Type a Name in the Box Below First Name: Suggestions: This example consists of three pages:
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#10
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The HTML Form
This is the HTML page. It contains a simple HTML form and a link to a javascript: Suggestions: Example Explained - The HTML Form As you can see, the HTML page above contains a simple HTML form with an input field called "txt1". The form works like this:
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