When the input file has been specified, Stat/Transfer by default selects all of the variables for transfer. A message will appear below the input File Specification line, telling you that all of the variables in the data set have been selected and giving the total number of variables.
If you wish to transfer all of the variables of the input data set, you need do nothing more to specify them. If you want to select only some of the variables in the input data set, click on the Variables tab at the top of the Transfer dialog box.
Once you have finished selecting variables, when you return to the Transfer dialog box, the number of variables you have chosen will appear.