Creating new object

A newbie question here : I don t get how to create a new object without using the magical line : @your_object = Object.new(param[:object])

I have a grid with a size, I would like to create the case associate to the grid at the creatin on the grid, I have try the following in the grid controller:

def create     @grid= Grid.new(params[:grid])     ((@grid.taille)-1).times do |i| //don t pay attention to the loop, and the attribution of corrdinate, it s not a square grid         ((@grid.taille)-1).times do |j|           @case = Case.new(params[:case])           @case.x = i           @case.y = -j           @case.grid_id = @grid.id           if @case.save             flash[:notice] = 'Case' + i +' '+ j + ' was successfully created.'         end     end .. end

But it return an error : "wrong number of arguments (0 for 1)" Hope you can help me. Thx