I have gone through the steps so many times and made sure that my forge matches 1.5.1. I do not know why it is crashing if somebody could try to help me the crash report is at the bottom of this post. I use MinecraftSP.

Minecraft has crashed!
----------------------

Minecraft has stopped running because it encountered a problem; Failed to start game

A full error report has been saved to C:\Users\Dad\AppData\Roaming\.minecraft\crash-reports\crash-2013-03-27_17.25.17-client.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash



--- BEGIN ERROR REPORT 4bcdffc2 --------
Full report at:
C:\Users\Dad\AppData\Roaming\.minecraft\crash-reports\crash-2013-03-27_17.25.17-client.txt
Please show that file to Mojang, NOT just this screen!

Generated 3/27/13 5:25 PM

-- System Details --
Details:
Minecraft Version: 1.5.1
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.6.0_32, Sun Microsystems Inc.
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Sun Microsystems Inc.
Memory: 399999808 bytes (381 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: FML is installed
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v7.44 FML v5.1.8.613 3 mods loaded, 3 mods active
mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed
FML [Forge Mod Loader] (coremods) Unloaded->Constructed
weaponmod [Balkon's WeaponMod] (weaponmod) Unloaded->Errored
LWJGL: 2.4.2
OpenGL: ATI Radeon HD 3400 Series GL version 3.3.10151 Compatibility Profile Context, ATI Technologies Inc.
Is Modded: Definitely; Client brand changed to 'fml'
Type: Client (map_client.txt)
Texture Pack: JohnSmith_V97_5019723.zip
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null

cpw.mods.fml.common.LoaderException: java.lang.ClassNotFoundException: weaponmod.BalkonsWeaponMod
at cpw.mods.fml.common.LoadController.transition(LoadController.java:142)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:512)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:160)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:310)
at net.minecraft.client.MinecraftAppletImpl.func_71384_a(SourceFile:56)
at net.minecraft.client.Minecraft.run(Minecraft.java:607)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: weaponmod.BalkonsWeaponMod
at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:211)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at cpw.mods.fml.common.ModClassLoader.loadClass(ModClassLoader.java:56)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:446)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:165)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:98)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:502)
... 5 more
Caused by: java.lang.NullPointerException
at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:200)
... 32 more
--- END ERROR REPORT 2de94a43 ----------