public String whichBinary(String type)
	{
		for (int i = 0; i < Expression.binaryTypes.length; i++) 
		{
			if (type.equals (Expression.binaryTypes[i])) 
			{
				if(type.equals("plus")||type.equals("minus")||type.equals("times")
						||type.equals("divided by"))
				{
					return "operator";
				}
				else if(type.equals("or")||type.equals("and"))
				{
					return "logic";
				}
				else
				{
					//"equals", "greater than", "less than"
					return "compare";
				}
			}
		}
		return null;
	}