I'm trying to optimize some kind of process in Mathematica. I did it without any problems in Matlab and now I'm trying to do the same in Mathematica which I don't know at all. I'm trying to find the best value of variable u for my proces, but that's not what I'm going to ask. My code at least should print eleven values of variable 'wynik' but it doesn't. I suppose that I've got some stupid and minor mistake in syntax, but as I've said earlier - I'm new at Mathematica environment. Any thoughts?

    For[u == 1, u <= 1, u == u + 0.1,  
        s = NDSolve[{x1'[t] == u*(10*x2[t] - x1[t]),  x1[0] == 1,   
                    x2'[t] == u*(x1[t] - 10*x2[t]) - (1 - u)*x2[t], x2[0] == 0}, 
                     {x1, x2}, {t, 0, 1}];  
        wynik == 1 - Evaluate[{x1[1] /. s} + {x2[1] /. s}]; 
        Print[wynik]]