html java script div content value change using id

1var targetDiv = document.getElementById('content');
2    var htmlContent = '';
3
4    function populateData(event){
5      switch(event.target.value){
6        case 'A':{
7         htmlContent = 'Content for A';
8          break;
9        }
10        case 'B':{
11          htmlContent = "content for B";
12break;
13        }
14      }
15      targetDiv.innerHTML = htmlContent;
16    }