HTML/CSS/Frame Attributes/marginwidth
"marginwidth" sets the left and right margins in pixels
<source lang="html4strict">
<HTML> <frameset rows="50,*" frameborder="yes" border="20px" framespacing="5" cols="*">
<frame name="topFrame" scrolling="NO" noresize src="http://www.wbex.ru"> <frameset cols="25%,*" border="15px" framespacing="0"> <frame name="leftFrame" marginheight="100" marginwidth="15" noresizescrolling="NO" src="http://www.wbex.ru"> <frame name="mainFrame" src="http://www.wbex.ru"> </frameset>
</frameset> </HTML>
</source>