How can I move to the next trial without generating new window of figure?

I'm working on generating attention shift task. And I'm very beginner of MATLAB. When I run this code, it kept generating new figure window. However, I want to make it goes to the next trial without generating new window with the figure. Could someone tell me what did I wrong? Thanks a lot!

DATA = zeros(80,1); % pre-allocation of data matrix
ExoHorizentalV100 = 0;
jj = 1; 
while ExoHorizentalV100 < 80
    coin = rand;
    if coin < 0.5 % cue and target presented in the right
        fig = figure;        
        set(fig,'position',get(0,'ScreenSize'))
        r1 = rectangle('position',[0,150,100,100],'EdgeColor','k','Linewidth',3);
        xlim([0 400])
        ylim([0 400])
        hold on
        plot(200,200,'+','MarkerSize',30,'LineWidth',3,'Color','k');
        hold on
        r2 = rectangle('position',[300,150,100,100],'EdgeColor','k','Linewidth',3);
        axis square;
        axis off;
        pause(4)
        t = text(180,270,'\rightarrow','FontSize',40,'LineWidth',3,'Color','k');
        pause(0.1) 
        set(t,'Visible','off')
        plot(350,200,'kp','MarkerSize',30,'MarkerFaceColor','k')
        pause(0.3)
        elseif coin > 0.5 % cue and target presented in the left
        fig = figure; 
        set(fig,'position',get(0,'ScreenSize'))
        r1 = rectangle('position',[0,150,100,100],'EdgeColor','k','Linewidth',3);
        xlim([0 400])
        ylim([0 400])
        hold on
        plot(200,200,'+','MarkerSize',30,'LineWidth',3,'Color','k');
        hold on
        r2 = rectangle('position',[300,150,100,100],'EdgeColor','k','Linewidth',3);
        axis square;
        axis off;
        pause(4)
        t = text(180,270,'\leftarrow','FontSize',40,'LineWidth',3,'Color','k');
        pause(0.1) 
        set(t,'Visible','off')
        plot(50,200,'kp','MarkerSize',30,'MarkerFaceColor','k')
        pause(0.3)
        end
    tic; pause ; temp = toc;
    response = get(fig,'CurrentCharacter');
    ExoHorizentalV100 = ExoHorizentalV100 + 1;
    DATA(jj,1) = temp;
    jj = jj + 1;
end

Answer 1

[Greg]

Take

        fig = figure;        
        set(fig,'position',get(0,'ScreenSize'))

out of the loop

[Jinah Lee]

Thank you so much Greg!!!!!!!!!