when n is number of player: function FullScreen(n){ try{ var p=window.document.getElementById("player"+n); if (p.playState==3) { if(gFullScr>0) { window.document.getElementById("player"+gFullScr).fullScreen= 'false'; } gFullScr=n; p.fullScreen = 'true'; } } catch(err){ ;} } I have 1-4 media players with my own controls on webpage, I do fullscreen to one of it, after that other players can't do fullscreen and throw exception. the command p.fullScreen = 'true'; throws exception , there is no problem with the first the js file: http://www.nrg.co.il/images/video/player2/player3.js