Google Map API教程之使用GControl对象在地图上添加control按钮

function control() {};
control.prototype = new GControl();
control.prototype.initialize = function(gmap){
var buttonDiv = document.createElement("div");
buttonDiv.id = "control";
buttonDiv.appendChild(document.createTextNode("清除标点"));
buttonDiv.onclick = function(){
gmap.clearOverlays();
};
gmap.getContainer().appendChild(buttonDiv);
return buttonDiv;
};

control.prototype.getDefaultPosition = function(){
return new GControlPosition(G_ANCHOR_TOP_LEFT, new GSize(510, 7));
};