Google maps 谷歌地图API v3 drawingManager全部删除

我有两个按钮（图像）。第一个将只删除选定的形状（并且它可以工作）。第二个必须删除地图上的所有覆盖图（我不知道该怎么做）

我确信这里的错误：

 var line = e;
line.type = e.type;

但是我不知道怎么做。 哪个变量存储多段线数组

谢谢

  function setSelection(shape) {
    clearSelection();
    selectedShape = shape;
    shape.setEditable(true);
  }
    function deleteSelectedShape() {
    if (selectedShape) {
      selectedShape.setMap(null);
    }
  }
  .......   
  function deleteAllShape(newPolygon) {
     if (newPolygon) {
         for (i in newPolygon) {
            newPolygon[i].setMap(null);
        }
         newPolygon.length = 0;
         }
      }
..........
drawingManager = new google.maps.drawing.DrawingManager({
.......});


 google.maps.event.addListener(drawingManager, 'overlaycomplete', function(e) {
        if (e.type != google.maps.drawing.OverlayType.MARKER) {
         var line = e;
         line.type = e.type;
         var newShape = e.overlay;
         newShape.type = e.type;

        google.maps.event.addListener(newShape, 'click', function() {
          setSelection(newShape);
        });
        setSelection(newShape);


        google.maps.event.addListener(line, 'polylinecomplete', function() {
        deleteAllShape(line);
    });
      }


    });

可能的重复可能的重复