Bug 141255 No error for the incompatible parameter value
Steps to reproduce: 1.New a decimal parameter, set the default value to "aaa" 2.Preview the report by "Preview" tab Expected result: Error to say the incompatible parameter value Actual result: Parameter request page keeps poping up till input the decimal value Note: if preview in Web Viewer, error will be thrown out, but no exception description.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/presentation/aggregation/parameter/ComboBoxParameterFragment.java
ParameterDefinition paramDef = parameterBean.getParameter( );
 		if ( paramDef.getGroup( ) != null && paramDef.getGroup( ).cascade( ))
		{
			Map paramValues = attrBean.getParameters( );
			selectionList = getParameterSelectionListForCascadingGroup(
					attrBean.getReportDesignHandle( request ), service, paramValues, options );
		} else
			selectionList = service.getParameterSelectionList(
					attrBean.getReportDesignHandle( request ), options,	parameter.getName( ) );
		parameterBean.setValueInList( false );
		if ( selectionList != null )
		{
			ReportParameterConverter converter = new ReportParameterConverter(
					parameter.getPattern( ), locale );
			for ( Iterator iter = selectionList.iterator( ); iter.hasNext( ); )
			{
				ParameterSelectionChoice selectionItem = ( ParameterSelectionChoice  ) iter
						.next( );
				String value = converter.format( selectionItem.getValue( ) );
				String label = selectionItem.getLabel( );
				label = ( label == null || label.length( ) <= 0 ) ? value
						: label;
				label = ParameterAccessor.htmlEncode( label );
				if ( label != null )
				{
					parameterBean.getSelectionList( ).add( label );
					parameterBean.getSelectionTable( ).put( label, value );
				}
				if ( value != null && value.equals( parameterBean.getValue( ) ) )
				{