Seamless frames in aspx frameset

[Just D.]

Does anybody know how to create a seamless frameset? If I try to use a right
click on the form in .NET IDE it breaks the whole form, even if I can get
the checkbox "Seamless" checked it actually doesn't help and I see the lines
between my frames both on design time or on run-time. Maybe I need to add
anything else?

The code is used:

<frameset border="0" frameSpacing="0" rows="75,80%,30" style="OVERFLOW:
hidden" bordercolor=#ffffff>
<frame name="header" src="FrameHeader.aspx" scrolling="no" style="OVERFLOW:
hidden" noResize bordercolor=#ffffff>
<frame name="main" src="FrameMain.aspx" scrolling="no" style="OVERFLOW:
hidden" noResize bordercolor=#ffffff>
<frame name="footer" src="FrameFooter.aspx" scrolling="no" style="OVERFLOW:
hidden" noResize bordercolor=#ffffff>
</frameset>


Just D.