function zoom(param)
{
	if(param=="plus")
	{
	map.zoomIn()
	}
	
	else
	{
	map.zoomOut()
	}
}


function deplacement(param)
{
	var bounds=map.getBounds();
	var span = bounds.toSpan();
	
	var newS = bounds.getSouthWest().lat();
	var newN = bounds.getNorthEast().lat();
	var newW = bounds.getSouthWest().lng();
	var newE = bounds.getNorthEast().lng();
	
	var milieu_lat=newN-((newN-newS)/2);
	var milieu_long=newE-((newE-newW)/2);
	
	if(param=="haut")
	{
		
		center=new GLatLng(newN, milieu_long);
		map.panTo(center);
	}
	
	if(param=="bas")
	{
		
		center=new GLatLng(newS, milieu_long);
		map.panTo(center);
	}
	
	if(param=="gauche")
	{
		
		center=new GLatLng(milieu_lat, newW);
		map.panTo(center);
	}
	if(param=="droite")
	{
		
		center=new GLatLng(milieu_lat, newE);
		map.panTo(center);
	}
}