Help on how to make an element that pops up when something in the Db changes?

[Infernette]

It's more of someone can push a button on your profile and it causes a value to change in the db, which changes your end without you refeshing. I was hoping to use it for a battle-esq system(person clicks attack, updates your end and shows you lost hp). I know javascript would be useful for sure, not so sure if it'll work with the mysidia page setup.