//前提是google earth 已經在頁面加載 即 ge!= null 否則報錯
function removeAllMarker()
{
var allChildren = ge.getFeatures().getChildNodes();
for(i=0;i<allChildren.getLength();i++)
{
if(allChildren.item(i).getType() == 'KmlPlacemark')
{
ge.getFeatures().removeChild(allChildren.item(i));
}
}
}