appendChild .vs. innerHTML vs. document.write

    if (document.createTextNode) {
      //append HTML to DOM
      var ic = document.createElement('div');
        ic.setAttribute('id','interContainer'); //var headerText = document.createTextNode(this.defineheader); ic.appendChild(headerText);
        ic.innerHTML += headerText;
      var icnt = document.createElement('div');
        icnt.setAttribute('id','interContent');
        icnt.setAttribute('onmouseover','interstitialBox.showcontainer().timervar.pause()');
        icnt.setAttribute('onmouseout','interstitialBox.showcontainer().timervar.resume()');
      ic.appendChild(icnt);
      var iveil = document.createElement('div');
        iveil.setAttribute('id','interVeil');
      ic.appendChild(iveil);
      document.getElementById('interstitial').appendChild(ic);
    }
    else if (document.getElementById) {
      document.getElementById('interstitial').innerHTML += '<div id="interContainer">'+this.defineheader+'<div id="interContent" onmouseover="interstitialBox.showcontainer().timervar.pause();" onmouseout="interstitialBox.showcontainer().timervar.resume();"></div></div><div id="interVeil"></div>';
    }
    else {
    document.write('<div id="interContainer">'+this.defineheader+'<div id="interContent" onmouseover="interstitialBox.showcontainer().timervar.pause();" onmouseout="interstitialBox.showcontainer().timervar.resume();"></div></div><div id="interVeil"></div>');
    }