If you're using b2evolution then you can just add :-

.bSideItem form h4{border-bottom:2px solid #f00}

to your style sheet, change the size and colour to suit your needs

the code you gave me , puts the line over the ALL of the Category...

I need the line between Categories... in fact a line inside the category..

I exaplined look Over.

The code I gave should have underlined all of the h4 tags in the catagory list , which is what you appear to want.

Try this bit of css and see if it works, if not then post a link to your blog so I can see the source.

.bSideItem li ul {border-top:1px solid #f00}

Thanx It works...
my blog adress is www.rojbash.net

but I tested it on my own local host and will will publish it later

thanks again.

no problem ;)