How to add a frame into the sidebox?

I'm using Avonlee Contempo template.
How to add a frame into the sidebox , just like the sidebox of the COMSTOCK Template.

If I understand what you are asking correctly
This is created with an image and css

.sideBoxContent {
	margin: 0;
	padding: 0 0.3em 1em 0.3em;
	background-image:url(../images/sidebox_content_bg.gif);
	background-repeat:no-repeat;
	background-position:bottom;
	line-height: normal;
	}

kobra:

If I understand what you are asking correctly
This is created with an image and css

.sideBoxContent {
margin: 0;
padding: 0 0.3em 1em 0.3em;
background-image:url(../images/sidebox_content_bg.gif);
background-repeat:no-repeat;
background-position:bottom;
line-height: normal;
}

Yes, it's exactly what I wanted.
I copied the image of the frame from the comstock and added the above code into the css.
thank you very much.,