The frameborder attribute of the FRAMESET element specifies whether or not to display a frame border.
<frameset cols="200,*" frameborder="0">
| Attribute | Value | Explanation |
|---|---|---|
| frameborder=" " | 0 | the border is not displayed |
| 1 | the border is displayed (default) |
Extension attribute. (Non standard attribute)
The difference of display
When you specify 0, the frame border is displayed as follows.

Internet Explorer, Opera : A small space remains.
Firefox : The border disappears completely.
The width of the frame border can be changed using the border attribute.
When the frame border is not displayed, that border might not be able to be moved.
<html> <head> <title>TAG index</title> </head> <frameset cols="200,*" frameborder="0"> <frame src="example_a.html"> <frame src="example_d.html"> <noframes> <body> <p>Alternate content</p> </body> </noframes> </frameset> </html>