what is this error pls

what is this error pls

 this is my own, IDE underlines dot before "is" in read, meaning it's an error.. what is the error...

if ( $('.fakeRadioButton' this ).is('.fakeSelected')) {
  • $
  • (this ).addClass('bg_white');
  • }
     
    compare w/this, from jQuery site,
     
    1. if
    ($(event.target).is('li') ) {
  • $
  • (event.target).css('background-color', 'red');
  • }
     
    thank you..
     
     
    (PS: there's something wrong w/editor in this window, once I make a font-change, I can't do it again to another paragr.. same thing happened yesterday...   (I think code should autom. be in courier new font.. I hate code in these stupid "proportional" fonts..)