var ajax = false;
function getXhttp(){
   var ajax=false;
    if (window.ActiveXObject){
        var mSoftVersions = ['MSXML2.DOMDocument.5.0','MSXML2.DOMDocument.4.0','MSXML2.DOMDocument.3.0','MSXML2.DOMDocument.2.0','MSXML2.DOMDocument','Microsoft.XmlDom','Msxml2.XMLHTTP','Microsoft.XMLHTTP'];
        for (i=0; i<mSoftVersions.length; i++){
            try {
                ajax = new ActiveXObject (mSoftVersions[i]);
            } catch (e){}
        }
    }else if(!ajax && typeof XMLHttpRequest != 'undefined'){
        try {
            ajax = new XMLHttpRequest;
        }catch(e){}
    }else if(!ajax && window.createRequest){
        try {
            ajax = window.createRequest;
        }catch(e){}
    }else{
        ajax = false;
    }
    return ajax;
}

function execAjax(xtarget,xparams,xmethod){
	var iXml = getXhttp();
	if (xmethod == 'POST'){
		iXml.open('POST', xtarget,true);
		iXml.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		iXml.send(xparams);
	}else{
		iXml.open('GET', xtarget + xparams,true);
		iXml.send(null);	
	}
	iXml.onreadystatechange = function () {
		if (iXml.readyState == 4) {
			if (iXml.status == 200) {
				if (iXml.responseText == 'true'){
					document.getElementById('er').style.display='none';
					document.getElementById('ok').style.display='block';
					document.getElementById('sending').style.display='none';
					document.getElementById('txtmsg').value = '';
				}else{
					document.getElementById('er').style.display='block';
					document.getElementById('ok').style.display='none';
					document.getElementById('sending').style.display='none';
				}
			}
		}
	};		
}