Lua Code:
frame.sBtn:SetScript("OnClick", function(self)
newFrame:SetShown(not newFrame:IsShown())
end)
Essentially, change the frame's shown state to what it is not now.
If you wanted to hide frame at the same time, add
Code:
self:GetParent():SetShown(not self:GetParent()IsShown())
to the above script. This assumes you have created the button (sBtn) with "frame" as its parent.
If you have a button on newFrame to toggle back, use the same script in its OnClick handler only replace newFrame with frame