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
}
	private void saveAggregate( ) throws Exception
	{
		if ( getBinding( ) == null )
		{
			this.newBinding.setName( txtName.getText( ) );
			this.newBinding.setDisplayName( txtDisplayName.getText( ) );
			for ( int i = 0; i < DATA_TYPE_CHOICES.length; i++ )
			{
				if ( DATA_TYPE_CHOICES[i].getDisplayName( )
						.equals( cmbType.getText( ) ) )
				{
					newBinding.setDataType( DATA_TYPE_CHOICES[i].getName( ) );
					break;
				}
			}
			this.newBinding.setExpression( cmbDataField.getText( ) );
			this.newBinding.setAggregateFunction( getFunctionByDisplayName( cmbFunction.getText( ) ) );
			this.newBinding.setFilterExpression( txtFilter.getText( ) );
			this.newBinding.clearAggregateOnList( );
			String aggStr = cmbAggOn.getText( );
			StringTokenizer token = new StringTokenizer( aggStr, "," );
			while ( token.hasMoreTokens( ) )
			{
				String agg = token.nextToken( );
				if ( !agg.equals( ALL ) )
					newBinding.addAggregateOn( agg );
			}
			this.binding = DEUtil.addColumn( getBindingHolder( ),
					newBinding,