Saving dnumslider value?

[kraffslol]

I'm trying to save the value from the slider so the next time I open the DERMA window it will remember what I put in the last time. How do I do this? I've tried several things and it currently looks like this:
[lua]
NumSlider = vgui.Create( "DNumSlider", DermaPanel )
NumSlider:SetPos( 25,50 )
NumSlider:SetWide( 150 )
NumSlider:SetText( "Volume:" )
NumSlider:GetValue()
NumSlider:SetMin( 0 ) -- Minimum number of the slider
NumSlider:SetMax( 100 ) -- Maximum number of the slider
NumSlider:SetDecimals( 0 ) -- Sets a decimal. Zero means it's a whole number
NumSlider:SetConVar( "lbc_volume" ) -- Set the convar
NumSlider.ValueChanged = function(pSelf, fValue)
print(fValue)
volym1 = fValue
end
NumSlider:SetValue(volym1)
end
[/lua]

[editline]10:03PM[/editline]

No one knows? :(