function getHTTPObject() {
	var req;
	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;
			}
		}
	}
	return req;
}

var req2 = getHTTPObject();

function BuscaLinha(id_cidade)
{
	
	//alert('cidade = ' + id_cidade);
	
	document.getElementById('linhaSelect').innerHTML = '<img src="images/loadingfotos.gif" border="0" />';
	
	req2.open("POST", "carrega_linhas_lo.php?id_cidade="+id_cidade, true);
	
	req2.onreadystatechange = function() 
	{
		if(req2.readyState == 4) 
		{
			
			var html = req2.responseText;
			
			var lista = document.getElementById("linhaSelect");
			
			lista.innerHTML = html;
			
			lista.style.display = "block";
			
		}
	};
	
	req2.setRequestHeader('Content-Type', 'text/html; charset=iso-8859-1');
	req2.send("");
}