DScrollPanel problems

This is my code for my DScrollPanel and the DPanelList that’s inside it. For some reason my list is unscrollable. Not sure why this is. Any suggestions?

	local scrollpanel = vgui.Create( "DScrollPanel", jobs )
		scrollpanel:SetSize( 500, 500 )
		scrollpanel:SetPos ( 20, 5 )

	local categoryList = vgui.Create("DPanelList", scrollpanel);
		categoryList:SetSize(450, 450)
		categoryList:SetSpacing( 5 )

Here’s an image of how it looks in-game:


Worked beautifully, thanks!