Minecraft crashes when I log in

---- Minecraft Crash Report ----
// Quite honestly, I wouldn't worry myself about that.

Time: 2/07/13 4:54 PM
Description: Rendering screen

java.lang.NoClassDefFoundError: org/lwjgl/util/glu/Project
	at bli.b(SourceFile:325)
	at bli.c(SourceFile:412)
	at bli.a(SourceFile:446)
	at bet.b(SourceFile:718)
	at atn.S(SourceFile:685)
	at atn.d(SourceFile:618)
	at net.minecraft.client.main.Main.main(SourceFile:101)
Caused by: java.lang.ClassNotFoundException: org.lwjgl.util.glu.Project
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	... 7 more


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at bli.b(SourceFile:325)
	at bli.c(SourceFile:412)
	at bli.a(SourceFile:446)

-- Screen render details --
Details:
	Screen name: bli
	Mouse location: Scaled: (410, 217). Absolute: (821, 44)
	Screen size: Scaled: (427, 240). Absolute: (854, 480). Scale factor of 2
Stacktrace:
	at bet.b(SourceFile:718)
	at atn.S(SourceFile:685)
	at atn.d(SourceFile:618)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.1
	Operating System: Windows Vista (x86) version 6.0
	Java Version: 1.7.0_10, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 20128048 bytes (19 MB) / 69251072 bytes (66 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.6.1
	LWJ