Solved
Be aware that different browsers DO render stuff on screen differently in some very specific situations. For the most part, everything SHOULD be generic, but I've encountered a few minor differences. So, when setting up for looping a test through multiple browsers, you may need to add some conditionals in order to account for these minor differences.
Way more information is needed. What doesn't work? Can you not create the loop, does it error when it runs? Examples of your script would be helpful as well.
There is no information to go off here.