Bug 10654 Allow all jars in a folder to be added to build path
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/VariableSelectionBlock.java
fVariableStatus= variableUpdated();
		} else if (field == fExtensionField) {
			fExtensionStatus= extensionUpdated();
		}
		fExistsStatus= getExistsStatus();
		updateFullTextField();
		
		fContext.statusChanged(StatusUtil.getMostSevere(new IStatus[] { fVariableStatus, fExtensionStatus, fExistsStatus }));
	}		
	
	private IStatus variableUpdated() {
		fVariable= null;
		
		StatusInfo status= new StatusInfo();
		String name= fVariableField.getText();
		if (name.length() == 0) {
			if (!fIsEmptyAllowed) {
				status.setError(NewWizardMessages.getString("VariableSelectionBlock.error.entername")); 
			} else {
				fVariable= ""; 
			}
		} else if (JavaCore.getClasspathVariable(name) == null) {
			status.setError(NewWizardMessages.getString("VariableSelectionBlock.error.namenotexists")); 
		} else {
			fVariable= name;
		}
		fExtensionField.enableButton(fVariable != null);
		return status;
	}