boxed xanga, this code wont work?? help Options

[xtrashx]

help... i want to put a box around my xanga entries but the code i used to use isnt workin, where should i put it.. is it right?

<!-- begin code provided by createblog.com --><br /><!-- begin code provided by createblog.com --><br /><style type="text/css"><br />.custom{<br />width: 520px; <br />height: 200px; <br />z-index:100; <br />overflow: auto; <br />border: px #ffffff solid; <br />background: #000000; <br />}</style><br /><!-- end code provided by createblog.com --><br /><!-- end code provided by createblog.com -->

it had the scrollbar on the sides thas what im tryin to get back