Make a 1-D array of booleans (you can use a boolean control, or a check box control from the Dialog Controls pallette). Put the 1-D array of booleans and the 2-D array of strings in a cluster. Adjust the size of the boolean control so that the boolean rows line up with the string rows. The user can click one of the boolean controls for the row he or she is interested in. To read which row the user checked, unbundle the boolean array from the cluster, then find the index of the row using the Search 1D Array function. You can use the Event Structure to determine when the user has clicked on a boolean control.