function setMapZoomLevels(){
   var minMapScale = 1;
   var maxMapScale = 10;
   mymap = new GMap2(document.getElementById("map_div"));
   mymap.addControl(new GLargeMapControl());
   var mymapTypes = mymap.getMapTypes();
   for (var i=0; i < mymapTypes.length; i++){
     mymapTypes[i].getMinimumResolution = function() {return minMapScale;}
     mymapTypes[i].getMaximumResolution = function() {return maxMapScale;}
   }
}

document.observe('dom:loaded', function() {
  setMapZoomLevels()
});