Bug 8476 JAR Packager: Make main class field editable
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarManifestWizardPage.java
fMainClassText.setText(fJarPackage.getMainClassName());
		} else if (!fJarPackage.isMainClassValid(getContainer())) {
			
			fJarPackage.setMainClass(null);
			fMainClassText.setText(fJarPackage.getMainClassName());
		}
	}
	protected void handleSealPackagesDetailsButtonPressed() {
		SelectionDialog dialog= createPackageDialog(fJarPackage.getPackagesForSelectedResources());
		dialog.setTitle(JarPackagerMessages.getString("JarManifestWizardPage.sealedPackagesSelectionDialog.title")); 
		dialog.setMessage(JarPackagerMessages.getString("JarManifestWizardPage.sealedPackagesSelectionDialog.message")); 
		dialog.setInitialSelections(fJarPackage.getPackagesToSeal());
		if (dialog.open() == dialog.OK)
			fJarPackage.setPackagesToSeal(getPackagesFromDialog(dialog));
		updateSealingInfo();
	}
	protected void handleUnSealPackagesDetailsButtonPressed() {
		SelectionDialog dialog= createPackageDialog(fJarPackage.getPackagesForSelectedResources());
		dialog.setTitle(JarPackagerMessages.getString("JarManifestWizardPage.unsealedPackagesSelectionDialog.title")); 
		dialog.setMessage(JarPackagerMessages.getString("JarManifestWizardPage.unsealedPackagesSelectionDialog.message")); 
		dialog.setInitialSelections(fJarPackage.getPackagesToUnseal());
		if (dialog.open() == dialog.OK)
			fJarPackage.setPackagesToUnseal(getPackagesFromDialog(dialog));
		updateSealingInfo();
	}
	/**
	 * Updates the enable state of this page's controls. Subclasses may extend.
	 */
	protected void updateEnableState() {
		boolean generate= fGenerateManifestRadioButton.getSelection();