regarding Y axis fontsize

[preeti gaikwad]

Hello all, 
           please help me to increase the font size in Y axis I am writing command

set(gca,'Ytick','FontSize', 20,'Fontname','arial');

is that wrong???

for x axis IF I do that

set(gca,'Xtick',0:1:10);

set(gca,'FontSize',20,'Fontname','arial');

set(gca,'linewidth',3)

then its correct but how to do same for y axis?????

second problem how to put bold letters for x and y and titles???? thanks a lot in advance 
-- 
preeti gaikwad