<script>         var map = new BMap.Map('allmap');         var Bcenter = new BMap.Point(116.404,39.915);         map.centerAndZoom(Bcenter,11);         //自定义控件         function staticControl(){             this.defaultAnchor = BMAP_ANCHOR_TOP_LEFT;             this.defaultOffset = new BMap.Size(10,10);         }         //继承Control的API         staticControl.prototype = new BMap.Control();         //初始化控件         staticControl.prototype.initialize=function(map){             var div = document.createElement('div');             var e1 = document.createElement('input');             e1.type = 'button';             e1.value = '重置';             e1.onclick=function(){                 statics();             }             div.appendChild(e1);             var e2=document.createElement('input');             e2.type = 'button';             e2.value = '缩小';             e2.onclick=function(){                 endStatics();             }             div.appendChild(e2);             var e3 = document.createElement("input");             e3.type = "button";             e3.value = "放大";             e3.onclick = function () {                setStatics();             }             div.appendChild(e3);             //添加DOM元素到地图中             map.getContainer().appendChild(div);             //返回DOM             return div;         }         //创建控件实例         var staticsCtrl = new staticControl();         //添加到地图当中         map.addControl(staticsCtrl);         function statics(){             map.centerAndZoom(new BMap.Point(116.404, 39.915), 11);         }         function endStatics(){             map.setZoom(map.getZoom()-2);         }         function setStatics(){             map.setZoom(map.getZoom()+2)         }     </script>