combobox and auto width

[gurpal2000]

I want the combobox to really display auto width (ie. resize the box to the largest item on a single line in the dropdown (all items preloaded).
I guess i want panelWidth to be the same as the component width, but both should be the width of the widest item. The width (default: auto) doesn't seem to auto anything. How i configure the component to do what i need?

thanks