worked it out I just changed the word click to mouseover in the following listeners
GEvent.addListener(marker_0, 'click', function() {
marker_0.openInfoWindowHtml(address_0.infowindowtext);
});
changed to
GEvent.addListener(marker_0, 'mouseover', function() {
marker_0.openInfoWindowHtml(address_0.infowindowtext);
});