yahoo pains!

Is there anyway i can keep my yahoo mail for oging to the "session expired" screen when i let my computer set over a minute? When I check my mail if i don't check it all at once i have to re-login anytime i go to another page or open a tab then try to go back to messages. Or when i open my login and mybe go answer then phone,if i don;t keep the window active every 30-40 seconds i have to relogin ah-gin. Is ther anyway i can fix this!?!?!?!?!

 

My time and date are right. But I can't seem to find anywhere in yahoo to set the cookie thing?I hate to ask but can you be real specific about the Control panel and stuff? Oh, and it's only yahoo that does it. I can walk away from this page for a day and still be logged in.!