arcgis desktop - Adding file name to attribute field using Calculate Field?

Does anybody know how to add the shapefile name to a field in the file's attribute table?

I've found a description:

'You have to use inline variable in CalculateField like %Name% in expresssion so that whatever the name of the file is, the string will be inserted based on Name of the dbase file !'

I've tried to CalculateField tool with %Name%, but I got message:

Executing: CalculateField "2011-11-6 15_41_point" DBFName %Name% PYTHON #
Start Time: Thu Dec 08 23:34:23 2011

WARNING 000405: No records within table
Succeeded at Thu Dec 08 23:34:24 2011 (Elapsed Time: 1.00 seconds)

Where is my mistake?

Answer

This python code adds FILENAME field to all Featureclasses (excluding those in Datasets) and populates with featureclass name.

# Import standard library modules
import arcpy, os, sys
from arcpy import env


# Allow for file overwrite
arcpy.env.overwriteOutput = True

# Set the workspace directory 
env.workspace = r"P:\geodatabase.gdb\filename" 

# Get the list of the featureclasses to process
fc_tables = arcpy.ListFeatureClasses()

# Loop through each file and perform the processing

for fc in fc_tables:
    print str("processing " + fc)

    # Define field name and expression
    field = "FILENAME"
    expression = str(fc) #populates field   

    # Create a new field with a new name
    arcpy.AddField_management(fc,field,"TEXT")


    # Calculate field here
    arcpy.CalculateField_management(fc, field, '"'+expression+'"', "PYTHON")