How to plot variable in structure using plot tools?

I have a structure variable defined in workspace,let's say; S.time=[0 1 2 3 4]; S.velocity=[0 10 20 30 40];

I want to plot S.time vs S.velocity using plot tools window. On plot tools window, I can do it by right clicking on figure and choosing add data and then filling x,y data source appropriately. It is OK but, in real, my structure "S" has hundred of variables inside and I have trouble to write correctly my variables names in x,y data source window. Any way to select the variables in structure using varibles editor window in plot tools.

Thanks for your replies.