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/context/ViewerAttributeBean.java
.lastModified( )
					|| ParameterAccessor.isOverwrite( request ) )
			{
				reportDocFile.delete( );
			}
		}
	}
	/**
	 * Get report service instance.
	 */
	protected IViewerReportService getReportService( )
	{
		return BirtReportServiceFactory.getReportService( );
	}
	/**
	 * Clear our resources.
	 * 
	 * @exception Throwable
	 * @return
	 */
	protected void __finalize( ) throws Throwable
	{
	}
	/**
	 * get parameter object.
	 * 
	 * @param request
	 * @param parameterObj
	 * @exception Throwable
	 * @return