function Ajax() {
    this.req = null;
    this.url = null;
    this.method = 'GET';
    this.async = true;
    this.status = null;
    this.statusText = '';
    this.postData = null;
    this.readyState = null;
    this.responseText = null;
    this.responseXML = null;
    this.handleResp = null;
    this.responseFormat = 'text', // 'text', 'xml', or 'object'
    this.mimeType = null;

this.init = function() {
    if (!this.req) {
        try {
            // Try to create object for Firefox, Safari, IE7, etc.
            this.req = new XMLHttpRequest();
            }   
        catch (e) {
            try {
                // Try to create object for later versions of IE.
                this.req = new ActiveXObject('MSXML2.XMLHTTP');
                }
            catch (e) {
                try {
                    // Try to create object for early versions of IE.
                    this.req = new ActiveXObject('Microsoft.XMLHTTP');
                    }
                catch (e) {
                    // Could not create an XMLHttpRequest object.
                    return false;
                    }
                }
            }
        }
    return this.req;
};

this.doReq = function() {
    if (!this.init()) {
        alert('Could not create XMLHttpRequest object.');
        return;
    }
    this.req.open(this.method, this.url, this.async);
    var self = this; // Fix loss-of-scope in inner function
    this.req.onreadystatechange = function() {
        var resp = null;
        if (self.req.readyState == 4) {
            switch (self.responseFormat) {
                case 'text':    resp = self.req.responseText;   break;
                case 'xml' :    resp = self.req.responseXML;    break;
                case 'object':  resp = req;                     break;
                }
            if (self.req.status >= 200 && self.req.status <= 299) 
                self.handleResp(resp);
            else 
                self.handleErr(resp);
            }
    }
    if (this.postData)this.req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    this.req.send(this.postData);
};

this.setMimeType = function(mimeType) {
    this.mimeType = mimeType;
};

this.handleErr = function() {
    var errorWin;
    try {
        errorWin = window.open('', 'errorWin');
        errorWin.document.body.innerHTML = this.responseText;
        }
    catch (e) {
        alert('An error occurred, but the error message cannot be '
            + 'displayed. This is probably because of your browser\'s '
            + 'pop-up blocker.\n'
            + 'Please allow pop-ups from this web site if you want to '
            + 'see the full error messages.\n'
            + '\n'
            + 'Status Code: ' + this.req.status + '\n'
            + 'Status Description: ' + this.req.statusText);
        }
};

this.setHandlerErr = function(funcRef) {
    this.handleErr = funcRef;
};

this.setHandlerBoth = function(funcRef) {
    this.handleResp = funcRef;
    this.handleErr = funcRef;
};

this.abort = function() {
    if (this.req) {
        this.req.onreadystatechange = function() { };
        this.req.abort();
        this.req = null;
    }
};

this.doGet = function(url, hand, format) {
    //this.req.setRequestHeader("Content-Type", "text/xml");
    this.url = url;
    this.method = 'GET';
    this.handleResp = hand;
    this.responseFormat = format || 'text';
    this.doReq();
};


}