remaining time from db with no page refresh

[panos100m]

hi in my php page i am showing to the user the remaining time untill an event occurs..
I am reading the value from a database
The problem is that he needs to refresh the page to get the correct time (for time to decrement) ...i can use a meta refresh but it doesn't look professiona, is there a way for the values to decrement without page refresh and if yes how? (can you please provide a code snip-set)
The only way that i can think maybe is by using an ajax function that queries the db every now and then but i am not sure how to call it as you normally associate it with events (like onclick, onscroll) or how to associate a timer.. but this might be the wrong thought ..

any help really appreciated!

Thanks

[hsriat]

You need to Ajax as you said. As far as calling this function is concerned, you can use setTimeout (example) to call this function after a specified time interval.