Bug 209126 DataException throws out when set highlight condition in sub-report[0302]
Description: Set highlight condition in sub-report, when "select value..." in the highlight dialog, DataException throws out. Build version:2.3.0.v20071108-0800 Steps to reproduce: 1.Get the attached report design file, which contains a sub-report. 2.Select the inner table, and then go to "highlight" tab in the property editor view to set a highlight rule. When click "select value...", DataException throws out. Error: The expression's value can not be retrieved. An error happened in data type conversion. Can not convert the value of org.eclipse.birt.data.engine.script.DataExceptionMocker@79c17b to Integer type.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/HighlightRuleBuilder.java
{
			StructuredSelection selection = (StructuredSelection) tableViewer.getSelection( );
			if ( selection.toList( ).size( ) <= 0 )
			{
				enabled = false;
			}
		}
		editBtn.setEnabled( enabled );
		delBtn.setEnabled( enabled );
		enabled = table.getItemCount( ) > 0 ? true : false;
		delAllBtn.setEnabled( enabled );
	}
	
	protected void checkAddButtonStatus( )
	{
		if ( addExpressionValue != null && ( !addExpressionValue.isDisposed( ) ) )
		{
			String value = addExpressionValue.getText( );
			if ( value == null
					|| value.length( ) == 0
					|| value.trim( ).length( ) == 0 )
			{
				addBtn.setEnabled( false );
				return;
			}
			if ( value != null )
			{
				value = value.trim( );
			}
			if ( valueList.indexOf( value ) < 0 )