Error

2011-10-16 13:10:59 [SEVERE] java.lang.Throwable
2011-10-16 13:10:59 [SEVERE] 	at de.diddiz.Superpickaxe.Superpickaxe.onCommand(Superpickaxe.java:63)
2011-10-16 13:10:59 [SEVERE] 	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
2011-10-16 13:10:59 [SEVERE] 	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:163)
2011-10-16 13:10:59 [SEVERE] 	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:355)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:757)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:722)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:715)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:33)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:92)
2011-10-16 13:10:59 [SEVERE] 	at org.getspout.spout.SpoutNetServerHandler.a(SpoutNetServerHandler.java:500)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:471)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:374)
2011-10-16 13:10:59 [SEVERE] 	at net.minecraft.server.ThreadServerApplication.run(SourceFile:417)
2011-10-16 13:10:59 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'spa' in plugin Superpickaxe v0.4d
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:163)
	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:355)
	at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:757)
	at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:722)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:715)
	at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:33)
	at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:92)
	at org.getspout.spout.SpoutNetServerHandler.a(SpoutNetServerHandler.java:500)
	at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
	at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:471)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:374)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:417)
Caused by: java.lang.NullPointerException
	at de.diddiz.Superpickaxe.Superpickaxe.onCommand(Superpickaxe.java:64)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
	... 13 more