function increment_corners(){ 
   	counter_corners++;
	if(counter_corners>345)
	{
	counter_corners=1;
	}
   	objcorners.style.background = "url(images/elevator/corners/"+counter_corners+".gif) no-repeat";  
}
	
function decrement_corners(){ 
   	counter_corners--;
	if(counter_corners<1)
	{
	counter_corners=345;
	}
   	objcorners.style.background = "url(images/elevator/corners/"+counter_corners+".gif) no-repeat";  
}

function increment_floor(){ 
   	counter_floor++;
	if(counter_floor>342)
	{
	counter_floor=1;
	}
   	objfloor.style.background = "url(images/elevator/floors/"+counter_floor+".gif) no-repeat";  
}
	
function decrement_floor(){ 
   	counter_floor--;
	if(counter_floor<1)
	{
	counter_floor=342;
	}
   	objfloor.style.background = "url(images/elevator/floors/"+counter_floor+".gif) no-repeat";  
}

function increment_walls(){ 
   	counter_walls++;
	if(counter_walls>346)
	{
	counter_walls=1;
	}
   	objwalls.style.background = "url(images/elevator/walls/"+counter_walls+".gif) no-repeat";  
}
	
function decrement_walls(){ 
   	counter_walls--;
	if(counter_walls<1)
	{
	counter_walls=346;
	}
   	objwalls.style.background = "url(images/elevator/walls/"+counter_walls+".gif) no-repeat";  
}