I have compiler error when i run the ant script

Hi

Iam a beginner working with ant...When I run the script I get the following error...let me know if you have any suggestions....

build:

[javac] Compiling 28 source files to C:\finaltrial\classes

[javac] Note: Some input files use unchecked or unsafe operations.

[javac] Note: Recompile with -Xlint:unchecked for details.

[javac] Compiling 186 source files to C:\finaltrial\classes

[javac] error: error reading C:\finaltrial\classes\trial\impl\ru

ntime\AbstractUnmarshallingEventHandlerImpl.class; error in opening zip file

[javac] Note: Some input files use unchecked or unsafe operations.

[javac] Note: Recompile with -Xlint:unchecked for details.

[javac] 1 error

Thanks in advance..

[766 byte] By [sragkotaa] at [2007-11-26 19:22:23]