Mozilla Firefox and Google chrome download problems?

when ever i download something on Firefox it downloads it but the (open) is not in black and i can't click it. for Google chrome when i double click the tab at the bottom when it say download complete i double click it and nothing ever come please help.|||Have you tried opening the downloaded files on their containing folder? Try to open them first.. If still it cannot be opened, try restarting the system and open the files again. Hope it works.