How to get the odd number output from Fl_Slider and Fl_Value_Slider?

[Dr. Furqan]

Hi, I don't know what's wrong with Fl_Slider and Fl_Value_Slider that I am not getting the odd number output.
In the following source code, look at the "value" and the "step" values. With these values the output should be 1, 3, 5, 7, 9, 11, so on... because the incremental step value is 2 which should be added in the initial value which is 1.
But what I am getting is 1, 2, 4, 6, 8, 10, so on...

    Fl_Slider* slider = new Fl_Slider(0, 0, 135, 20);
    slider->box(FL_UP_BOX);
    slider->align(FL_ALIGN_LEFT);
    slider->type(FL_HOR_SLIDER);
    slider->minimum(1);
    slider->maximum(99);
    slider->value(1);
    slider->step(2);
    slider->callback(_slider_cb, (void*)this);

Please help me to solve this issue? By the way, Fl_Spinner is working totally fine.
Thank you.