Bug 198504 The same name aggregation should be hint in dialog[0001]
Description: The same name aggregation should be hint in dialog[0001] Step: 1.New a datasource, dataset, table and binding the dataset. 2.New a aggregation column binding on table named aggr1. 3.Drop a aggregation item into table and set the named as aggr1. 4.Click OK Actual result: Pop up an error message said that the name is exist. Expected result: It can hint in dialog when input the same name, but pop up an error dialog
xtab/org.eclipse.birt.report.item.crosstab.ui/src/org/eclipse/birt/report/item/crosstab/internal/ui/dialogs/CrosstabBindingDialogHelper.java
cmbAggOn = new Combo( composite, SWT.BORDER | SWT.READ_ONLY );
		cmbAggOn.setLayoutData( new GridData( GridData.FILL_HORIZONTAL
				| GridData.GRAB_HORIZONTAL ) );
	}
	private void createCommonSection( Composite composite )
	{
		new Label( composite, SWT.NONE ).setText( EXPRESSION );
		txtExpression = new Text( composite, SWT.BORDER );
		txtExpression.setLayoutData( new GridData( GridData.FILL_HORIZONTAL
				| GridData.GRAB_HORIZONTAL ) );
		createExpressionButton( composite, txtExpression );
		txtExpression.addModifyListener( new ModifyListener( ) {
			public void modifyText( ModifyEvent e )
			{
				validate( );
			}
		} );
	}
	protected void handleFunctionSelectEvent( )
	{
		Control[] children = argsComposite.getChildren( );
		for ( int i = 0; i < children.length; i++ )
		{
			children[i].dispose( );
		}
		String function = getFunctionByDisplayName( cmbFunction.getText( ) );
		if ( function != null )
		{
			argsMap.clear( );
			List args = getFunctionArgNames( function );