Creating More Complex Layouts
A single frameset can have any number of rows and columns, but they must be in a regular rectangular grid. In other words, you can’t define a single frameset with one column in the first row and two columns in the second row. Unlike with table cells, there is no way to merge or split frames.
Therefore, if you need different numbers of rows or columns, you must embed one frameset within another. For example, here’s some code that creates a layout of a single frame across the top and two side-by-side frames beneath it. You can make rows and columns any size; in the following example the height of the top yellow frame is 86 pixels and the width of the left blue frame is 136 pixels.
<frameset rows="86,*"> <frame src="yellow.htm" ...