I have been able to use the Import script step to import pictures from a folder. However, doing the same for bunch of pdf and word document files have not been a success. Is there any special trick to achieve this?

"have not been a success" is not a good description of a problem. Please describe exactly what you did and how it failed.

my apologies... here is what I did, I imported a folder, using the import script step, on the Import Field Mapping dialogue, I Mapped the File Name field to my Title field, then Image is mapped to my Container Field..

I used this reference http://www.filemaker.com/help/14/fmp/en/html/import_export.18.16.html#1044791

I re tried the steps again this morning, and it worked.. I have checked my scripts back and forth, didn't modify anything, I don't really know why didn't work initially.

However, I did specify the folder for the import, but right now, I want to give my users the option of selecting their own folders.

I have tried that by leaving the specify Folder option blank (unspecified), but and my script runs through without given an option to choose a folder. This is where I am stuck right now.