Handles for multiple random squares?

I am trying to write a script that plots N random squares, then allows the user to click on the figure window. If the point is in a square, the square turns red. I can plot N random squares and have created a function that determines if a point is in a square, but I can only get it to work for one square, not multiple squares. Here is my code so far:

N=2;
hold on
i=(1:N);
for i=1:N
    b=rand(size(i));
    d=rand(size(i));
    c=[b,d];
    e=rand(size(i));
    h=plot_a_square(c,e);
end
while true
    [x,y]=ginput(1);
    p=[x,y];
    z=zeros(size(i));
    in_a_square(p,c,e)
    for z=1;
        set (h,'Color','r')
        hold off
    end
end

The plot_a_square code:

    function h=plot_a_square(c,e)
    x=[c(1)-.5*e,c(1)-.5*e, c(1)+.5*e,c(1)+.5*e,c(1)-.5*e];
    y=[c(2)-.5*e,c(2)+.5*e, c(2)+.5*e,c(2)-.5*e,c(2)-.5*e];
    h=plot(x,y);
    end

The in_a_square code

function z=in_a_square(p,c,e)
if p>=c(1)-0.5*e & p<=c(1)+0.5*e & p>=c(2)-0.5*e & p<=c(2)+0.5*e
    z=true;
else
    z=false;
end
end

I know I need to create an array of the handles, and I think I need an array of the z values, but I don't know where to go from there. Thoughts?