run function from event

why doesn't this work?

Code:java

@EventHandler
public void DeathEvent(PlayerDeathEvent e){
      //Code blablabla
      Player k = e.getEntity().getKiller();
      ...
      //Call the function
      addKill(k.getName());
}
 
//Below the function
public void addKill(String player) {
    mysql sql = this.plugin.getMySQL();
    sql.queryUpdate("UPDATE stats SET kills = kills+1 WHERE name ='" + player + "'");
}

and if i run this code i get this error:

Code:

Could not pass event PlayerDeathEvent to Main_System v1.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at org.bukkit.craftbukkit.v1_7_R3.event.CraftEventFactory.callPlayerDeathEvent(CraftEventFactory.java:349) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.EntityPlayer.die(EntityPlayer.java:373) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.EntityLiving.damageEntity(EntityLiving.java:732) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.EntityHuman.damageEntity(EntityHuman.java:746) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.EntityPlayer.damageEntity(EntityPlayer.java:452) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.EntityHuman.attack(EntityHuman.java:925) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:1105) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInUseEntity.a(SourceFile:55) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInUseEntity.handle(SourceFile:10) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:157) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:667) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:260) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:558) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
Caused by: java.lang.NullPointerException
    at listeners.deathListener.addKill(deathListener.java:82) ~[?:?]
    at listeners.deathListener.DeathEvent(deathListener.java:35) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_05]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_05]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-56-g3779cff-b3072jnks]
    ... 19 more

okay found the error ^^ it was here:

Code:java

//Error Code
public deathListener(main main) {
    this.plugin = plugin;
}
 
//Corect Code
public deathListener(main plugin) {
    this.plugin = plugin;
}

EDIT by Moderator: merged posts, please use the edit button instead of double posting.