function createXMLHttp(){
	var xmlHttp;
	try
	{
		xmlHttp = new XMLHttpRequest();
	}
	catch(e)
	{
		var version = new Array('MSXML2.XMLHTTP.6.0',
								'MSXML2.XMLHTTP.5.0',
								'MSXML2.XMLHTTP.4.0',
								'MSXML2.XMLHTTP.3.0',
								'MSXML2.XMLHTTP',
								'Microsoft.XMLHTTP');
		var len = version.length;
		for(var i=0; i<len && !xmlHttp; i++)
		{
			try
			{
				xmlHttp = new ActiveXObject(version[i]);
			}
			catch(e){}
		}
	}
	if(!xmlHttp){
		alert('Error create XMLHttpRequest');
	}else{
		return xmlHttp;
	}
}