How to change marker size in Google Maps V3

This my code but it is not showing difference How Would I change the size of the markers give me some syntaxs

var mapOptions1 = {
center: new google.maps.LatLng(-34.397, 150.644 ),
zoom: 5
};
//var size1 = new google.maps.Size(100, 71);
 var image = {
    url: 'http://chart.apis.google.com/chart?chst=d_map_pin_letter&chld=ccTLD|800000',
    // This marker is 20 pixels wide by 32 pixels tall.
    size: new google.maps.Size(500, 200),
    // The origin for this image is 0,0.
    origin: new google.maps.Point(0,0)
  };
var infoWindow1 = new google.maps.InfoWindow();
var map1 = new google.maps.Map(document.getElementById("map_canvas"), mapOptions1);
for (i = 0; i < bmarkers.length; i++) {
var data1 = bmarkers[i]
var myLatlng1 = new google.maps.LatLng(data1.lat, data1.lng);
var marker1 = new google.maps.Marker({
position: myLatlng1,
map: map1,
icon: image,
//size: size1,
title: data1.title
}
);