var tP=0; var eF=0; function failed() {eF=1} var popWin = window.open("","ptest","width=1,height=1,left=5000,top=5000",true); window.onerror=failed var pW = window.open("","ptest","width=1,height=1"); eF = pW == popWin ? 0 : 1; popWin.blur(); popWin.close(); tP = eF == 0 ? 1 : 0; window.onerror=null; if(tP == 1){ document.write(""); }