I’m creating a plugin for wordpress using only php and css (for now at least) where it generates a topbar with a number of messages choosed by the user, i need to know how i can generate an ‘if’ statement that activates autoscroll only when text’s lenght of 1 or more messages or the sum of all texts’ lenght exceeds the screen’s width

I have some js files that are not loading. The code works sound if I use <script> //js code </script> in the page template but not if I try and load the script from a separate file.