[nerv_]

<div id="test"></div>

<script>
    var case1 = '123123 <b>7</b> asdads';
    var case2 = ' <div> asdnaslklj ';

    var box = document.getElementById( 'test' );
    
    box.innerHTML = case1;
    alert( case1 === box.innerHTML );

    box.innerHTML = case2;    
    alert( case2 === box.innerHTML );
</script>