function update_map(event)
{
	event.preventDefault();

	var lat = document.getElementById('lat').value;
	var lon = document.getElementById('lon').value;

	request_url = new URL("/render/map.svg", document.URL);
	request_url.searchParams.append("lat", lat);
	request_url.searchParams.append("lon", lon);

	var request = new XMLHttpRequest();
	request.open("GET", request_url);

	request.addEventListener('load', function(event) {
		if (request.status >= 200 && request.status < 300) {
			var svgblob = new Blob([request.responseText], { type: "image/svg+xml" });

			document.getElementById("svgcontainer").innerHTML = request.responseText;

			link_container = document.getElementById("downloadlink");
			link_container.innerHTML = '';

			var blobUrl = URL.createObjectURL(svgblob);

			var link = document.createElement("a"); // Or maybe get it from the current document
			link.href = blobUrl;
			link.download = "map.svg";
			link.innerHTML = "Download this map.";
			link_container.appendChild(link); // Or append it whereever you want

			URL.revokeObjectURL(blobUrl);
		} else {
			console.warn(request.statusText, request.responseText);
		}
	});

	request.send();
}