HTML/CSS/Frame Attributes/marginheight
"marginheight" sets the size, in pixels, of the top and bottom margins of a frame
<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>