port 80 not working

i have a server with cent os 6 x64
in this server port 80 dont work .
when i installed apache 2.4.x with custombuild all of my website opens with https but dont open with http for example :
when i type my ip in browser with https i see this : Apache is functioning normally
but when i try without https i dont see that .

i have the problem with all website .
how can i solve this problem ?
tnx