Ajax From the Ground Up: Part 1 - XMLHttpRequest | Impressive Webs

function getXhrObject() {  

    var xhrObject = false;  

    // Most browsers (including IE7) use the 3 lines below  

    if (window.XMLHttpRequest) {  

        xhrObject = new XMLHttpRequest();  

    }  

    // Internet Explorer 5/6 will use one of the following  

    else if (window.ActiveXObject) {  

        try {  

        xhrObject = new ActiveXObject("Msxml2.XMLHTTP");  

            } catch(err) {  

                try {  

                xhrObject = new ActiveXObject("Microsoft.XMLHTTP");  

                } catch(err) {  

                xhrObject = false;  

                }  

        }  

    }  

    return xhrObject;  

} 

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