I have imported a dataset into SPSS from Excel. In the Excel file, not all cells contained a value (=missing value). Once imported into SPSS, those cells now contain a dot (.), as follows:
Code: 
VAR_X	VAR_Y	VAR_Z
------------------------
5,6384	5,9269	     .
     .	5,6384	     .
6,0186	5,6168       .
6,0039	6,0186	4,5322
     .	6,0039	4,1564
6,1420	6,0568	     .
5,9428	     .	     .
5,5373	5,9428	     .
However, looking at the "variable view" pane, it says there are no missing values in any of the variables. How can I tell SPSS to interpret the dot (.) as a missing value?