//var req;

function doRequest(url, processReqChange_Callback) {
        req = false; 
        // branch for native XMLHttpRequest object
        if(window.XMLHttpRequest) {
        try {
                        req = new XMLHttpRequest();
                } catch(e) {
                        req = false;
                }
        // branch for IE/Windows ActiveX version
        } else if(window.ActiveXObject) {
        try {
                req = new ActiveXObject("Msxml2.XMLHTTP");
        } catch(e) {
                try {
                        req = new ActiveXObject("Microsoft.XMLHTTP");
                } catch(e) {
                        req = false;
                }
                }
        }
        if(req) {
                req.onreadystatechange = processReqChange_Callback;
                req.open("GET", url, true);
                req.send("");
        }
}

function doPostRequest(url, parameters, processReqChange_Callback) {

        req = false; 
        // branch for native XMLHttpRequest object
        if(window.XMLHttpRequest) {
        try {
                        req = new XMLHttpRequest();
                } catch(e) {
                        req = false;
                }
        // branch for IE/Windows ActiveX version
        } else if(window.ActiveXObject) {
        try {
                req = new ActiveXObject("Msxml2.XMLHTTP");
        } catch(e) {
                try {
                        req = new ActiveXObject("Microsoft.XMLHTTP");
                } catch(e) {
                        req = false;
                }
                }
        }
        if(req) {
                req.onreadystatechange = processReqChange_Callback;
                req.open('POST', url, true);
  		        req.setRequestHeader("Content-type", "application/x-www-form-urlencoded; charset=UTF-8");
      		    req.setRequestHeader("Content-length", parameters.length);
                req.send(parameters);
        }
}