my world is not in the game on single player

The level.dat of your world file is broken. I get following error when loading your world:

java.util.zip.ZipException: Not in GZIP format
        at java.util.zip.GZIPInputStream.readHeader(Unknown Source)
        at java.util.zip.GZIPInputStream.<init>(Unknown Source)
        at java.util.zip.GZIPInputStream.<init>(Unknown Source)
        at cb.a(SourceFile:9)
        at ajk.c(SourceFile:54)
        at ajg.b(SourceFile:53)
        at avz.h(SourceFile:74)
        at avz.A_(SourceFile:64)
        at avw.a(SourceFile:98)
        at net.minecraft.client.Minecraft.a(SourceFile:448)
        at bhl.a(SourceFile:237)
        at avw.a(SourceFile:72)
        at bhl.a(SourceFile:468)
        at avw.d(SourceFile:127)
        at avw.m(SourceFile:111)
        at net.minecraft.client.Minecraft.l(SourceFile:1078)
        at net.minecraft.client.Minecraft.J(SourceFile:574)
        at net.minecraft.client.Minecraft.run(SourceFile:526)
        at java.lang.Thread.run(Unknown Source)

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i want to know how to fix it plz help

You could try renaming level.dat_old to level.dat (overwriting the existing one)... but it looks like you messed up your world with mcedit or with a standard crash.

Ok I will try that.

Ok so i tried this but the level.dat if i switch them but it does not show up at all only on mcedit in but my dad is going to look at and see what the problem is.