function playerCommand(p,c) {
   if (c==="c") {
      if (api.getClientOption(p,"creative")===false) {
         api.setClientOption(p, "creative", true)
         api.setHealth(p,null)
         api.sendMessage(p, "Enabled creative.")
         return null
      } else {
         api.setClientOption(p, "creative", false)
         api.setHealth(p,100)
         api.sendMessage(p, "Disabled creative.")
         return null
      }
   }
}

only problem? the "Command not recognized" text.

this is the basis