Applescript - telling multiple applications to do something?

Is there any easier way to tell several applications to do the same thing?

I have an Applescript that moves my browsers to the center of the display based on resolution and resizes them from top to bottom. Now I just repeat the script for each browser (Firefox, Chrome, Safari) by checking if the process exists and then telling the app to go to position and resize itself.

So basically is there a syntax to do "check if the browsers are open and then do the same things to each of them" without repeating the code for each browser?