People are requesting you write some information in a attempt to help you and you wont respond. What brand and model brakes, are they mechanical or hydraulic, what type of riding, what bike are they on.
So far you say the front disc brake doesnt work, it's a xnine?, you ride the bike and in the mud.
If they were working good before getting all muddy it could be they need to be cleaned as well as replacing the cable and housing. A cheater way of checking the housing is to disconnect the housing from the stops and see how freely it moves on the cable, odds are yours are seized or close to.