Question: ODEplot w/ multiple ICs, Graphics

I have the following differential equation:

(dy / dx) = (x* (1 - .5*x - .5*y) ) / (y* (-.25 + .5*x))

First, I would like to graph the solution to this equation with multiple initial conditions. For example, I would like to graph the solution with y(1) = 2, y(1) = 4, etc. Is this possible using the ODEplot command? If it is not possible using ODEplot, can you provide me with a command I can use and with sample code?

Second, I would like to create a nice graphic that labels the critical points of each solution (the critical points of y(1) = 2 solution and y(1) = 4 solution) and uses an arrow to point to the critical points. I am not familiar with how to use graphics in Maple; could someone provide me with sample code for this example?

Thanks very much!

Andy Hunt