Bug 103291 Group key doesn't support inputting text
Description: Group key doesn't support inputting text Steps to reproduce: 1.Add a table and bind it with data set 2.Add a group to the table: enter a row name in the "Group On:" textbox 3.Save and preview Expected result: Everything is OK Actual result: Error occurs because the group key is added as a string not a expression
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/GroupDialog.java
*            the parent composite
	 */
	private void createFilterSortingArea( Composite parent )
	{
		Group group = new Group( parent, SWT.NONE );
		group.setText( GROUP_DLG_GROUP_FILTER_SORTING );
		group.setLayout( new GridLayout( ) );
		group.setLayoutData( new GridData( 550, 250 ) );
		ArrayList list = new ArrayList( 1 );
		list.add( inputGroup );
		TabFolder tab = new TabFolder( group, SWT.TOP );
		tab.setLayoutData( new GridData( GridData.FILL_BOTH ) );
		TabItem filterItem = new TabItem( tab, SWT.NONE );
		filterPage = new FormPage( tab,
				FormPage.NORMAL_FUNCTION,
				new FilterHandleProvider( ) {
					public int[] getColumnWidths( )
					{
						return new int[]{
								200, 100, 100, 100
						};
					}
				} );
		filterPage.setInput( list );
		filterItem.setText( TAB_FILTER );
		filterItem.setControl( filterPage );
		TabItem sortItem = new TabItem( tab, SWT.NONE );
		sortPage = new FormPage( tab,
				FormPage.NORMAL_FUNCTION,
				new SortingHandleProvider( ) {