When you write a for loop or a while loop, be sure that the initial, final, and step values for the variable that controls the loop are correct. Incrementing a loop variable one time more or less than you really want is a common source of errors.
To ensure that a control loop works as you expect, click in the Silk Test Classic menu to step through the execution of the loop one statement at a time, and watch how the value of the loop variable changes using . See Stepping Into and Over Functions.