When a method is declared as private, the program compiles 
properly but it will give runtime error ?Main method not 
public"

IF MAIN METHOD IS DECLARED AS PRIVATE ,THEN WE CAN NOT 
ACESSES THE PRVIATE MEMBERS IN ANOTHER CLASS

Nothing Happen.
Code compiles properly and executes properly.

Wrong Vani.

The output of the program is

C:\>javac abc.java

C:\>java abc
Main method not public.

If the main function is made private...it will compile 
Sucessfully...and at the time of execution...it will 
execute successfully...but desired result will not be 
obtained. After execution..folowin message will be printed:
Main method not public.

it compile easily... but it will give an error at the time 
of execution .....

vani, varsha is correct , the 'private main method' is as
good as any member method your class can have (note that
main is not a key word in java) , it can be only used inside
the class in which it is defined. 

It is clearly mentioned in the specifications that the
executing class should contain a 'public static void method'
as a point of execution otherwise execution will fail
complaining ABOUT THE METHOD WHICH I MENTIONED ABOVE.

JVM is also a program. If main() is declared as privateit 
is not available outside of that class . So JVM through the 
exception.