Gets the value of the next element in a group. You can get the value of all the elements in a group. Call the GrpFirst() function to get the value of the first element, and then call this function in a loop.
The group handle, returned from the GrpOpen() function. The group handle identifies the table where all data on the associated group is stored.
The value returned from GrpFirst() or the latest GrpNext() call.
The value of the next element in a group, or -1 if the end of the group has been found.
! Count all values in a group.
WHILE Value<>-1 DO
Prompt("Number of values in group is "+Count:###);