var xmlHttp;
var xmlHttp1;

function cambiaCombo(fabricante,modelo,combustible,motor) {
	
	url = "buscador.php";	
	xmlHttp1=GetXmlHttpObject(stateChangedSubcategoria);

	params =  "fabricante="+fabricante+"&modelo="+modelo+"&combustible="+combustible+"&motor="+motor; 
	xmlHttp1.open("POST", url, true);
	xmlHttp1.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	xmlHttp1.setRequestHeader("Content-length", params.length);	
	xmlHttp1.send(params);
}

function stateChangedSubcategoria() 
{ 	
	if (xmlHttp1.readyState==4 || xmlHttp1.readyState=="complete")
	{ 
		document.getElementById("buscador").innerHTML=xmlHttp1.responseText;
	} 
}

function GetXmlHttpObject(handler)
{ 
	var objXmlHttp=null

	if (navigator.userAgent.indexOf("Opera")>=0)
	{
		alert("This doesn't work in Opera") 
		return 
	}
	if (navigator.userAgent.indexOf("MSIE")>=0)
	{ 
		var strName="Msxml2.XMLHTTP"
		if (navigator.appVersion.indexOf("MSIE 5.5")>=0)
		{
			strName="Microsoft.XMLHTTP"
		} 
		try
		{ 
			objXmlHttp=new ActiveXObject(strName)
			objXmlHttp.onreadystatechange=handler

			return objXmlHttp
		} 
		catch(e)
		{ 
			alert("Error. Scripting for ActiveX might be disabled") 
			return 
		} 
	} 
	if (navigator.userAgent.indexOf("Mozilla")>=0)
	{
		objXmlHttp=new XMLHttpRequest()
		objXmlHttp.onload=handler
		objXmlHttp.onerror=handler 
		return objXmlHttp
	}
}