Actually, the function of this trick just add a border at the bottom of your widgets. So, your blog will look attractive. Shortly, if you want to Add Border at the Bottom of Widgets, just follow the steps below.
1. Log in to your blogger account
2. Go to Design --> Edit HTML
3. Check in the "Expand Widget Templates" box
4. Find code like this (in some templates maybe not same)
.sidebar ul li {5. Copy the code below, and add under the code above
border-bottom:1px dotted #000000;6. Then click SAVE TEMPLATE
