[Harlow]How to Update a variable without loading the whole page again

i'v made a game who is full of interactives things but it need to refresh the page again and again every times and the position of the scroll is not even saved , the easyest way to resolve my problem will be to update the specific code who need to be refresh... for exemple , when i take an item , the page need to reload to take it in my hand , and then , when i click in the slot , it need to reload AGAIN to put it down ...

(im french , sorry for my bad english)