How to make the background like this
 

As shown in these pictures

Attachment 125592
this is the forumdisplay page

Attachment 125593
and this is the showthread page

how can i add background to the Even lines

thanks!

Open the Style Manager, choose Main CSS from the dropdown on the style of your choice, and find Second Alternating Color. Edit the options there.

If you want it to be a tiled image, add the following to the Extra CSS Attributes box:

background-image: url(*image here*);
background-repeat: repeat;

thanks,but it don't work

That's not a background image, that is either a mod or template edits to do this. There was a mod for VB 3.6 to do this, but it doesn't work on 3.8 and I couldn't find a newer version.