code:

var info = [ 'html', 'html', 'html' ];
var locs = [ '40', '-50', '42', '-51', '44', -56' ]; 

function drawmap() {
  if (GBrowserIsCompatible()) {
    map = new GMap2(document.getElementById("map_canvas"));

    var id = 1;
    while (locs.length > 0) { // While the array is populated...
      var point = new GLatLng(locs.shift(), locs.shift()); //locs is array of alternating lats and longs, shift it twice to get the coords back.
      map.addOverlay(createMarker(point, id));
      id++;
    }
  }
}

function createMarker(point, id) {
  var towerIcon = new GIcon(baseIcon);
	
  var marker = new GMarker(point);
  marker.value = id;
  GEvent.addListener(marker, "click", function() {
    var html = info[id-1];
    map.openInfoWindowHtml(point, html);
  });
  return marker;
}