Unable to upload an experimental data set to a graph

Hi,
I tried to upload an experimental data set to a graph but I had a problem following the recommended steps:

-Add series
-Source Type: File
-I chose the .txt file containing the experimental data set
-No possibilities appeared in the X-item and Y-item drop-down menu

I cheked the .txt file format:

i.e:

#.t      .S_NH4
#d      mg/m3
0        100
1        12
2        23
3        22
4        12

I hope you can help me...

The format looks correct. You should be able to load the data file in W2012 (and in W2014 soon).
What version are you using?
Also: please check that tabs are actually used as column separators and not e.g. spaces.

I'm using WEST2012
I cheked,  tabs are actually used as column separators
It's strange, my collegues with the same WEST version have not this kind of problem...

Indeed very strange. Will you please send us (mikebydhi) your text file, as is?
We can continue this discussion through the usual technical support channel.
Should anything relevant for other users emerge, we'll post it back here.