Refresh pages with Add function

Hi Everybody
On a webpage I have an agenda. Weekly I change the item and members can look who is coming to speak at the audience. In order to see the right version of that week I put the commando
meta http-equiv=“refresh” content=“30”> in the “Add” function. It worked, but a little while later I saw no results anymore. I also tried
meta http-equiv=“refresh” content=“30”
and placed the box as high as possible.
No results. It’s strange because it works earlier.
I think I do something wrong.
Thanks in advance! Greetzzzz Ton