Add content
as a property to marker object and use this.content
in the event handler:
var marker = new google.maps.Marker(options);
marker.content="<div>Content goes here....</div>";
var infoWindow = new google.maps.InfoWindow();
google.maps.event.addListener(marker, 'click', function () {
infoWindow.setContent(this.content);
infoWindow.open(this.getMap(), this);
});