Circle On 3d Axes

I am newbie in `Matlab`. I want to draw a circle on a 3d Axes and move the circle on mouse move.

I tried something like below code :

    function drag_patch
    figure('WindowButtonMotionFcn',@figButtonMotion);
    ax = axes;
    xlabel('x axis')
    ylabel('y axis')
    zlabel('z axis')
    view(-37.5,30);
    np = 2; % number of patches to create
    p = zeros(1,np); % patch handles
    x = cell(1,np); % shape x-values
    y = cell(1,np); % shape y-values
    % Create the Patches
    for k = 1:np
    sides = 50;
    psi = 2*pi*(0.03 + (0:sides-1)/sides);
    x{k} = cos(psi); % shape XData
    y{k} = sin(psi); % shape YData
    z{k} = sin(psi); % shape ZData
    clr = sqrt(rand(1,3)); % shape Color
    p(k) = patch(x{k}+5*randn,y{k}+5*randn,z{k},clr);
    set(p(k),'UserData',k,'ButtonDownFcn',{@patchButtonDown,p(k)});
    end
    axis equal
    patch_clicked = 0;
    this_p = p(1);
    this_k = 1;

    % Function for Identifying Clicked Patch
    function patchButtonDown(this,varargin)
        this_p = this;
        this_k = get(this,'UserData');
        patch_clicked = ~patch_clicked;
    end

    % Function for Moving Selected Patch
    function figButtonMotion(varargin)
        if patch_clicked
            % Get the Mouse Location
            curr_pt = get(ax,'CurrentPoint');
            % Change the Position of the Patch
            set(this_p,'XData',x{this_k}+curr_pt(1,1),'YData',y{this_k}+curr_pt(1,2));
        end
    end
    end

I achieved this,below image shows the result :

But i want something like this Circle:

%