How to resolve Conversion to Dalvik format failed with error 1 in Phonegap project?

Project shows this error because the phonegap jar (phonegap-1.0.0rc2.jar) /any other jar  file is not stored in the proper folder in the project setup.
I have created a Lib folder under src folder and placed the phonegap  jar into it and added the jar to buildpath which resulted in the error.


Resolution:
1) Remove the Phonegap jar/any other jar from the build path.
In the eclipse select project -> Properties ->Java Build Path.Select the tab libraries.Then select the phonegap jar and remove it.
2) Add the lib folder directly under the project(i.e not under any folders in project) and
 place the phonegap jar under it. Add the phonegap jar  to build path.
Then Clean and build the project.

Sample Exception stracktrace

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx

UNEXPECTED TOP-LEVEL EXCEPTION:

java.lang.IllegalArgumentException: already added: Lcom/phonegap/AccelListener;

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.dex.file.DexFile.add(DexFile.java:163)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.command.dexer.Main.processClass(Main.java:486)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.command.dexer.Main.processFileBytes(Main.java:455)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.command.dexer.Main.access$400(Main.java:67)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:394)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.command.dexer.Main.processOne(Main.java:418)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.command.dexer.Main.processAllFiles(Main.java:329)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.dx.command.dexer.Main.run(Main.java:206)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at java.lang.reflect.Method.invoke(Unknown Source)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.ide.eclipse.adt.internal.build.DexWrapper.run(DexWrapper.java:179)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.ide.eclipse.adt.internal.build.BuildHelper.executeDx(BuildHelper.java:585)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at com.android.ide.eclipse.adt.internal.build.builders.PostCompilerBuilder.build(PostCompilerBuilder.java:490)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:728)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:199)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:239)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:292)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:295)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:351)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:374)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:143)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:241)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)

[2012-01-03 18:57:54 - MedicalSalesManApplication] Dx 1 error; aborting

[2012-01-03 18:57:54 - MedicalSalesManApplication] Conversion to Dalvik format failed with error 1

[2012-01-03 18:58:45 - MedicalSalesManApplication] Dx