Top Cross Tester Lines Indicator Variable Use this option to specify the variable indicating the tester lines. When specified, top crosses are constructed between testers and non-tester lines. You must assign a value of 1 for the tester lines and 0 otherwise. To Specify a Top Cross Tester Lines Indicator Variable: Specify the input data set. All of the variables in the specified data set are displayed in the Available Variables field. Examine the list of available variables. Highlight the desired variable. Click to add the highlighted variable to the Top Cross Tester Lines Indicator Variable field, as shown below: