Applescript if class else

I have a applescript I have been using for a while and it works good:

set js to "document.getElementsByClassName('The_Class')[0].click();"

tell application "Google Chrome" to tell ¬
    the front window to tell ¬
    the active tab to ¬
    set jsResult to execute javascript js

Now I want to add a if and else to it. Like this but I can't find a way to solve it:

if the class ('The_Class') exist then

  set js to "document.getElementsByClassName('The_Class')[0].click();"

     tell application "Google Chrome" to tell ¬
       the front window to tell ¬
       the active tab to ¬
       set jsResult to execute javascript js

else

   tell application "Google Chrome" to activate

      tell application "System Events"
         keystroke "r" using {command down}
      end tell

end if