The "Select Cases" dialog box contains three major sections.

On the left is a select-list containing all the variables in the dataset.

On the upper right is a box labelled "Select" which contains five radio buttons to choose from.
These represent the five options for selecting cases from a dataset: use all cases (Alt+A);
If condition is satisfied (Alt+C); Random sample of cases (Alt+D); Based on time or case range (Alt+B);
and Use filter variable (Alt+ U).

On the lower right is a box labelled "Unselected Cases Are" with two radio button options: 
Filtered (Alt+F) or Deleted (Alt+L).

In this particular example, we are choosing "If condition is satisfied" (Alt+C). You may then hit Tab and
Enter to enter the "Select Cases: If" dialog box wherein you specify the condition. Alternatively, you can hit
Alt+C, then Alt+I, which will take you directly to the "Select Cases: If" box, which is described later in the
SPSS tutorial.

Once you have finished with the "Select Cases: If" box and have returned to the "Select Cases" box,
the OK button should already be highlighted, so you can simply hit Enter. Alternatively,
you may hit Alt+P to exit the box and paste the syntax into the syntax window.