[Beck]

if(all_lat_length > 1) {
	var i = 0;
	var i2 = 0;	

	if(m['mcount'] > 1) {
		while(i < m['mcount']){		
			while(i2 < all_lat_length) {
				if(m['lat'][i] == all_lat[i2] && m['lng'][i] == all_lng[i2]){m['lat'].splice(i,1);m['lng'].splice(i,1);m['mcount']--;}
				i2++;
				}
		i++;
		}
	}
	if(m['mcount'] == 1) {
		var i2 = 0;
		while(i2 < all_lat_length) {
			if(m['lat'] == all_lat[i2] && m['lng'] == all_lng[i2]){m['mcount'] = 0;}
			i2++;
			}			
		}
	}		
	

	
	if(m['mcount'] > 1) {	var i = 0;while(i < m['mcount']){insert_marker(m['lat'][i],m['lng'][i]);i++;}	}	
	if(m['mcount'] == 1) {	insert_marker(m['lat'],m['lng']);	}
	console.log(mcnt);

console.log(mcnt); должно выводить три, а выводит 4.