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
public void dialogFieldChanged(DialogField field) {
			doFieldUpdated(field);
		}
		
		
		public void changeControlPressed(DialogField field) {
			doChangeControlPressed(field);
		}
		
	}
	
	private void doChangeControlPressed(DialogField field) {
		if (field == fVariableField) {
			String variable= chooseVariable();
			if (variable != null) {
				fVariableField.setText(variable);
			}
		} else if (field == fExtensionField) {
			IPath filePath= chooseExtJar();
			if (filePath != null) {
				fExtensionField.setText(filePath.toString());
			}
		}
	}
	
	private void doFieldUpdated(DialogField field) {
		if (field == fVariableField) {