JS method of displaying line breaks in alert_javascript skills

The example in this article describes the method of displaying line breaks in alert using JS. Share it with everyone for your reference, the details are as follows:
Let’s first introduce a more complicated method, but this method can be used to distinguish any browser model:

//浏览器类型判定
function getOs()
{
  if(navigator.userAgent.indexOf("MSIE")>0) {
     return "IE"; //InternetExplor
  }
  else if(isFirefox=navigator.userAgent.indexOf("Firefox")>0){
     return "FF"; //firefox
  }
  else if(isSafari=navigator.userAgent.indexOf("Safari")>0) {
     return "SF"; //Safari
  }
  else if(isCamino=navigator.userAgent.indexOf("Camino")>0){
     return "C"; //Camino
  }
  else if(isMozilla=navigator.userAgent.indexOf("Gecko/")>0){
     return "G"; //Gecko
  }
  else if(isMozilla=navigator.userAgent.indexOf("Opera")>=0){
     return "O"; //opera
  }else{
    return 'Other';
  }
}
function alert_br(){
  var os=getOs();
  if(os=='FF' || os=='SF'){ //FireFox、谷歌浏览器用这个
    alert('第一行
第二行');
  }else{  //IE系列用这个
    alert('第一行
\n第二行);
  }
}
alert_br();

The second one is relatively simple, but it can only easily distinguish IE from other browsers:

function alert_br(){
  if(!document.all)//FF/{谷歌浏览器用这个
    alert('第一行
第二行');
  }else{  //IE系列用这个
    alert('第一行
\n第二行);
  }
}
alert_br();

I hope this article will be helpful to everyone in JavaScript programming.