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 createFieldArea( Composite parent )
	{
		Composite composite = new Composite( parent, SWT.NONE );
		composite.setLayout( new GridLayout( ) );
		GridData gd = new GridData( GridData.FILL_BOTH );
		gd.widthHint = 200;
		composite.setLayoutData( gd );
		
		new Label( composite, SWT.NONE ).setText( GROUP_DLG_GROUP_NAME_LABEL );
		
		nameEditor = new Text( composite, SWT.SINGLE | SWT.BORDER );
		nameEditor.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		
		new Label( composite, SWT.NONE ).setText( GROUP_DLG_GROUP_KEY_LABEL );
		
		keyChooser = new Combo( composite, SWT.DROP_DOWN );
		keyChooser.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		
		Composite intervalArea = new Composite( composite, SWT.NONE );
		intervalArea.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		intervalArea.setLayout( UIUtil.createGridLayoutWithoutMargin( 2, false ) );
		
		new Label( intervalArea, SWT.NONE ).setText( GROUP_DLG_GROUP_INTERVAL_LABEL );
		new Label( intervalArea, SWT.NONE ).setText( GROUP_DLG_GROUP_RANGE_LABEL );
		
		intervalType = new Combo( intervalArea, SWT.READ_ONLY | SWT.DROP_DOWN );
		intervalType.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		for ( int i = 0; i < intervalChoices.length; i++ )