public static String removeDups(String s)
	{
		char[] arr = s.toCharArray();
		if (arr == null) return null;
		if (arr.length < 2) return s;
		int end = 1;
		
		for(int i = 0; i<arr.length; i++)
		{
			int j = 0;
			for(; j<end; j++)
			{
				if(arr[i] == arr[j])
				{
					break;
				}
			}
			if (j==end)
			{
				arr[end] = arr[i];
				end++;
			}
		}
		return new String(arr, 0, end);
	}