Se me olvidó poner el codigo que he usado.
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false&language=es"></script>
<script type="text/javascript">
function initialize() {
var myLatlng = new google.maps.LatLng(41.640319, 2.16836);
var myOptions = {
zoom: 13,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canva s"), myOptions);
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
title:"Pedra Natural Garcia, SL"
});
var contentString = '<div id="content">'+
'<div id="siteNotice">'+
'</div>'+
'<h3 id="firstHeading" class="firstHeading">Pedra Natural Garcia, SL</h3>'+
'<div id="bodyContent">'+
'Ctra. Caldes-Sant Feliu km. 13.5</br>'+
'08140-Caldes de Montbui (Barcelona)'+
'<h2>93 865 48 40</h2>'+
'</div>'+
'</div>';
var infowindow = new google.maps.InfoWindow({
content: contentString,
maxWidth: 250
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.open(map,marker);
});
}
</script>
<div id="map_canvas" style="width:450; height:300"></div>