Marker Size in gMaps

HTML

<script src="http://maps.google.com/maps/api/js?sensor=false&amp;.js"></script>
<div id="results"></div>

<div id="map"></div>

CSS

#map{
    width: 450px;
    height: 400px;
}

JavaScript

function initialize(){
    var map;
    var centerPosition = new google.maps.LatLng(50.272213,-5.054973);
    var options = {
        'zoom': 12,
        'center': centerPosition,
        'mapTypeId': google.maps.MapTypeId.ROADMAP
    };

    map = new google.maps.Map(document.getElementById('map'), options);

    var circle = new google.maps.Circle({
        center: centerPosition,
        map: map,
        fillColor: '#0000FF',
        fillOpacity: 0.25,
        strokeColor: '#0000FF',
        strokeOpacity: 0.25,
        strokeWeight: 2
    });
    var circle2 = new google.maps.Circle({
        center: centerPosition,
        map: map,
        fillColor: '#0000FF',
        fillOpacity: 0.5,
        strokeColor: '#0000FF',
        strokeOpacity: 0.5,
        strokeWeight: 3
    });
        var circle3 = new google.maps.Circle({
        center: centerPosition,
        map: map,
        fillColor: '#FF0000',
        fillOpacity: 0.25,
        strokeColor: '#FF0000',
        strokeOpacity: 0.25,
        strokeWeight: 3
    });
    circle.setRadius(11111.55489862987); 
    circle2.setRadius(19000.55489862987); 
    circle3.setRadius(21000.55489862987); 
    
    map.fitBounds(circle2.getBounds());   
    
}
            
google.maps.event.addDomListener(window, 'onload', initialize());