Trying to add 1 to a integer

[water1108]

I am trying to make it so that when you click the button it adds 1 to the label every click.
The most I've gotten is so that it adds 1 and then just sits there. Any help is appreciated!
local Button = vgui.Create( "DButton", Frame )

Button:SetText( "Click" )
Button:SetSize( 250,75 )
Button:SetPos( 35 , 35 )

Button.Paint = function( self , w , h )

draw.RoundedBox( 4 , 0 , 0 , w , h , Color( 255 , 0 , 255 , 255 ))

end

Button.DoClick = function()

clicks = clicks + 1

Label:SetText( tostring(clicks) )

end