//above public form2 we need to put        
        Dictionary> car;



public Form2(Dictionary> car) // for examle using dictionary and class form form 1 in form 2
        {
            InitializeComponent();
            this.car = car; 
        }
//in form 1 we need to add this for it to work
            Form2 form = new Form2(car);
//by iq18but18cm