[Paraview] Unable to read .vtk file

[Marta Varela]

Hi.

I'm new to Paraview and have written a simple text file with a .vtk 
extension to be read by paraview. I have used the following syntax:

# vtk DataFile Version 2.0
vtk output
ASCII
DATASET STRUCTURED_POINTS
DIMENSIONS 210 1 120
ORIGIN 0 0 0
SPACING 1 1 1
POINT_DATA 25200
SCALARS ImageFile float 1
LOOKUP_TABLE default
-1000.000000
-1000.000000
-1000.000000
-1000.000000
-1000.000000
-1000.000000
-1000.000000
-1000.000000
...

Paraview is unable to read the file. Can you please explain why to me 
and what I can do to fix this?

Many thanks. Best wishes,
Marta