var dest, speed=1;			
			var upper_b=20;
			var lower_b2=-650;
			var reset;
			
			function scr(destination) {
				if(mo) {
					dest=destination;
					distance=parseInt(document.getElementById("Cities").style.top);
			
					window.status=distance+"";

					if(dest=='down' && distance<upper_b) {
						distance+=speed;
						reset=false;
					}
					if(dest=='up' && distance>lower_b2) {
						distance-=speed;
						reset=false;
					}
					if(reset) {
						if(distance<lower_b) {
							distance=lower_b2;
						}
						if(distance>upper_b) {
							distance=upper_b;
						}
						speed=1;		
					}
					document.getElementById("Cities").style.top=distance+'px';
					setTimeout("scr(dest)", 0);
				}
			}