JSFiddle - React, Tailwind, and code Playground

HTML

<span id="BugIDCopy" width=50px>[enter Bug ID]</span><input type="text" id="BugID" width=50px /><br/>
<span id="SummaryCopy" width=50px>[Enter Summary]</span><input type="text" id="Summary" width=50px />

JavaScript

var BugID=document.getElementById('BugID');
var BugIDCopy=document.getElementById('BugIDCopy');
var Summary=document.getElementById('Summary');
var SummaryCopy=document.getElementById('SummaryCopy');    

BugID.style.display="none";
Summary.style.display="none";



BugIDCopy.onclick=function(){
    BugIDCopy.style.display="none";
    BugID.style.display="";
    Summary.style.display="none";
    SummaryCopy.style.display="";
    BugID.focus();
};
SummaryCopy.onclick=function(){
    BugIDCopy.style.display="";
    BugID.style.display="none";
    Summary.style.display="";
    SummaryCopy.style.display="none";
    Summary.focus(); 
};

Summary.onkeyup=function(){
    SummaryCopy.innerHTML=this.value;
}
BugID.onkeyup=function(){
    BugIDCopy.innerHTML=this.value;
}