Google Maps Toggling Overlays With Checkbox - google-maps

Question

I'm stuck. I can't get my checkbox functional. I would like to toggle two layers with a checkbox. The two layers should be on when loaded (check box checked) and then turned off when unchecked. Simple, I know, but I can't get it functional despite looking at lots of working examples and checking all the posts. Most of the stuff I found were how it worked with KML and fusion tables. I have something working kinda that works for a button but this doesn't work well for check boxes.
Here is the code for the drop down box with the check boxes.
tileNEX = new google.maps.ImageMapType({
getTileUrl: function(tile, zoom) {
return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q-900913/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime();
},
tileSize: new google.maps.Size(256, 256),
opacity:0.50,
name : 'NEXRAD',
isPng: true
});
goes = new google.maps.ImageMapType({
getTileUrl: function(tile, zoom) {
return "http://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/goes-ir-4km-900913/" + zoom + "/" + tile.x + "/" + tile.y +".png?"+ (new Date()).getTime();
},
tileSize: new google.maps.Size(256, 256),
opacity:0.50,
name : 'GOES NA Vis',
isPng: true
});
//create the check box items
var radarOptions = {
gmap: map,
title: "This allows for selection/toggling on/off Radar layer",
id: "radarCheck",
label: "Radar",
action: function(){
if (map.overlayMapTypes.length==0) {
map.overlayMapTypes.push(null); // create empty overlay entry
map.overlayMapTypes.setAt("1",tileNEX);
}
else {
map.overlayMapTypes.clear();
}
}
}
var check1 = new checkBox(radarOptions);
var radarAnimate = {
gmap: map,
title: "This allows for selection/toggling on/off Animated Radar",
id: "radarAnimate",
label: "Animate Radar",
action: function(){
alert('Function is coming soon');
}
}
var check2 = new checkBox(radarAnimate);
var satOptions = {
gmap: map,
title: "This allows for selection/toggling on/off Satelite layer",
id: "satCheck",
label: "Satellite",
action: function(){
if (map.overlayMapTypes.length==0) {
map.overlayMapTypes.push(null); // create empty overlay entry
map.overlayMapTypes.setAt("1",goes);
}
else {
map.overlayMapTypes.clear();
}
}
}
var check3 = new checkBox(satOptions);
//create the input box items
//possibly add a separator between controls
var sep = new separator();
//put them all together to create the drop down
var ddDivOptions = {
items: [sep, check1, check2, check3],
id: "myddOptsDiv"
}
//alert(ddDivOptions.items[1]);
var dropDownDiv = new dropDownOptionsDiv(ddDivOptions);
var dropDownOptions = {
gmap: map,
name: 'Options',
id: 'ddControl',
title: 'A custom drop down select with mixed elements',
position: google.maps.ControlPosition.TOP_RIGHT,
dropDown: dropDownDiv
}
var dropDown1 = new dropDownControl(dropDownOptions);
FULL CODE
LINK TO MAP