function defilement(origine, destination){
  
  if (origine == undefined) {
  	origine = 0;
  }
  if (destination == undefined) {
  	destination = 200;
  }
  
  
  if (origine < destination) {
		
		for (var i= origine; i < destination; i++ ){
    	difference = destination - i;
    	if (difference > 100) {
    		i = i + 3;
    	} else if (difference > 50){
    		i = i + 2;
    	}
    	scrollTo(0,i);
  	}  	
  } else {
  	for (var i= origine; i > destination; i-- ){
    	difference = i - destination;
    	if (difference > 100) {
    		i = i - 3;
    	} else if (difference > 50){
    		i = i - 2;
    	}
    	scrollTo(0,i);
  	}
  }

}