Need Answer

Drop down list value fetching

My question arises because it would be useful that, once a row is selected in a drop down list (combo box), the value contained on a different column could be fetched and saved to a text box.

That is, for instance, if I select Product-type it would be nice to get its unit-price and put it in an adjacent cell.

Then, how can I fetch a value in a different column of a selected row and save it to a text box?

I tried with Actions & Validations, but it doesn't seem to work.

Thanks

Andrea