function ajaxInit(){
	var httprequest=false
	if (window.XMLHttpRequest){ // Se Mozilla, Safari etc.
		httprequest=new XMLHttpRequest()
		if (httprequest.overrideMimeType)
			httprequest.overrideMimeType('text/xml')
	} else if (window.ActiveXObject){ //Se IE
		try { httprequest=new ActiveXObject("Msxml2.XMLHTTP");} 
		catch (e){try{httprequest=new ActiveXObject("Microsoft.XMLHTTP");}catch (e){}}
	}
	return httprequest
}