Enabling and disabling List Box

I need to enable and disable the second list box based on selection in first list box. If the value of first box is "all", then second list box should be enabled. If the value is not "all" then second list box shoule be disapled. Any help should be greately appreciated.

you could use a dynamic double combo, so depending what is choosen in the first drop down alters what is shown in the second combo.

scroots