GiveIt 1.3 Console Error

2011-06-04 21:55:11 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'giveme' in plugin GiveIt v1.3
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:37)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:128)
	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:281)
	at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:718)
	at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:684)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:677)
	at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:32)
	at net.minecraft.server.NetworkManager.b(NetworkManager.java:217)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:75)
	at net.minecraft.server.NetworkListenThread.a(SourceFile:105)
	at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:401)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:311)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:422)
Caused by: java.lang.StringIndexOutOfBoundsException: String index out of range: -1
	at java.lang.String.substring(Unknown Source)
	at com.cianmcgovern.giveit.IdChange.idChange(IdChange.java:25)
	at com.cianmcgovern.giveit.GiveMe.giveme(GiveMe.java:35)
	at com.cianmcgovern.giveit.GiveIt.onCommand(GiveIt.java:190)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:35)
	... 12 more