Trying to trasnform GCS_Bessel_1841 PCS_Trasnverse Mercator (central meridian 18) to WGS1984 using "Project tool" in ArcGIS 9.3. I tried to do it in several different ways, every time from the beginning.

In project dialog box under Output coordinate system I choose

a) Select predefined PCS. I choose WGS PDC. Nothing happens. b) Select predefined GCS. I choose World/WGS_1984. Nothing happens. c) Import from an existing dataset. Nothing happens. d) I go to Layers, Transformations, select "Convert from GCS_Bessel_1841 to World/WGS_1984 (from the drop down menu). I select "using New Geographic Transformation" and choose position vector with seven variables which I got from here

http://georepository.com/transformation_3964/MGI-1901-to-WGS-84-4.html.

Nothing happens. The polygons remain the same, and the PCS is always the TM I started with.

Please help. Obvious ideas are welcome. As are a few short sentences behind the rationale of the system. I know what a PCS and GCS and datums are :) The country is Croatia.