Set DIV scroll bar

This is a very common task, basically through the CSS to implement the scroll bar.
scroll bar
Sets whether the scroll bar is displayed primarily by setting the following properties in CSS:

The code is as follows:
Overflow:visible|auto|hidden|scroll
Overflow-x: Horizontal scroll bar
OVERFLOW-Y: Vertical scroll bar

The meaning of the parameter:
Visible: Do not cut content or add scroll bars. If this default value is explicitly declared, the object is clipped to the size of the window or frame that contains the object. and the Clip property setting is invalidated.
Auto: This is the default value for the body object and textarea. Cut content and add scroll bars when needed
Hidden: Do not display content beyond the object size
Scroll: Always show scroll bars
Overflow:auto; This means that when your content exceeds the div height the vertical scroll bar appears
So we want to show the vertical scroll bar when we need to, so we can do this:

The code is as follows:
<divstyle= "Overflow:auto;" >...</div>

Set DIV scroll bar