如何使内容在div底部

如何插入一段漂亮的代码片

主要的就是这个段代码introduce.scrollTop = introduce.scrollHeight.

function switchs(lable){
        var lable1 = document.getElementById('lable1');
        var lable2 = document.getElementById('lable2');
        var qrCode = document.getElementById('qrCode');
        var introduce = document.getElementById('introduce')
        let qrCodeShow =''
        let detailsShow = ''
        if(lable=='lable1'){
            lable1.className='lable1'
            lable2.className='lable2'

            //底部样式更改
            qrCodeShow = ""
            qrCodeShow +="
"
            qrCodeShow +="
观看更多直播
"
            qrCodeShow +="
请长按右侧二维码
"
            qrCodeShow +="
识别并关注公众号
"
            qrCodeShow +="
"
            qrCode.innerHTML = qrCodeShow 

            detailsShow = "
讲题："+details.title+"
"
            detailsShow += "
时间："+details.time+"
"
            detailsShow += "
讲者："+details.doctor+"
"
            detailsShow += "
医院："+details.hosp+"
"
            detailsShow += "
介绍："+details.presentation+"
"
            introduce.innerHTML =detailsShow
        }else{
            lable2.className='lable1'
            lable1.className='lable2'

            //
            for(let i of comment){
                detailsShow +="
"
                detailsShow +=" "
                detailsShow +="
"
                detailsShow +=" 
"+ i.name+"
"
                detailsShow +=" 
"+ i.text+"
"
                detailsShow +=" 
"
            }
            introduce.innerHTML = detailsShow
            introduce.scrollTop = introduce.scrollHeight
            //底部样式更改
            qrCodeShow =" 
"
            qrCodeShow +=""
            qrCodeShow +="
发   表
"
            qrCodeShow +="
"
            qrCode.innerHTML = qrCodeShow 
            
           
        }
    }