Python script beginner error

i tryed the following python code
partly from WWW and partly from freebasic
code that i wrote earlyer
error
utils not recognised

import bpy
import utils
from math import pi , sin , cos , abs

verts = list()
faces = list()

def sphere_mesh( m , n , a , b ) :
    for col in xrange( m ) :
        for row in xrange( n ) :
            i = row * pi * 2 / n
            j = col * pi * 2 / m
            x = sin( i ) * cos( j )
            y = sin( j )
            z = cos( i ) * cos( j )
            point = ( abs( x ) ** da * sgn( x ) 
            , abs( y ) ** db * sgn( y ) 
            , abs( z ) ** da * sgn( z ) ) 
            point = surface(u, v)
            verts.append(point)
            # Connect first and last 
            # vertices on the u and v axis
            rowNext = (row + 1) % n
            colNext = (col + 1) % m
            # Indices for each qued
            faces.append(((col*n) + rowNext, 
            (colNext*n) + rowNext, 
            (colNext*n) + row, (col*n) + row))
    #print('verts : ' + str(len(verts)))
    #print('faces : ' + str(len(faces)))
    # Create mesh and object
    mesh = bpy.data.meshes.new(name+'Mesh')
    obj  = bpy.data.objects.new(name, mesh)
    obj.location = origin
    # Link object to scene
    bpy.context.scene.objects.link(obj)
    # Create mesh from given verts and faces
    mesh.from_pydata(verts, [], faces)
    #Update mesh with new data
    mesh.update(calc_edges=True)
    return obj




if __name__ == '__main__' :
    # Remove all elements
    utils.removeAll()
    # Create camera
    bpy.ops.object.add(type='CAMERA', 
    location=(0, -3.5, 0))
    cam = bpy.context.object
    cam.rotation_euler = Euler((pi/2, 0, 0), 'XYZ')
    # Make this the current camera
    bpy.context.scene.camera = cam
    # Create lamps
    utils.rainbowLights()
    # Create object and its material
    sphere = sphere_mesh( 12 , 12 , 2 , 2 )
    utils.setSmooth( sphere , 3 )
    utils.renderToFolder( 'rendering' , 
    'test_sphere' , 500 , 500 )

The “utils” in your code is from a custom Blender module written by Nikolai Janakiev. You have to download that module and import it into your script before you can use it.