How can I plot multiple data set on a single contour plot

Please can anyone urgently help? I need to know how I can plot 4 sets of data on a single contour plot in order to compare them and make a decision. I also need the contours to be unshaded so that lines of intersection can be seen. Lastly, the contour lines will need to be in colours in order to be identifiable. A 2D contour plot is what I am after I have tried so much that I have even learned and installed add-ins for my excel but can't get through. I have attached a file containing the four sets of data. Any help will be over appreciated.Optimum soln trial.xls