php - How to hide content and show the rest by scrolling -

i have project:

and want content scrolls inside grey box. not go under box or out of box.

how can this?

you need css limit height of grey box, , rest of content (incase it's higher hight gave) scrollable:

#grey_box { height:300px; overflow-y:scroll; } 

in code assumed grey box div id="grey_box" , height 200px. change values if it's not correct. important give height div, , overflow:scroll;