var oFra = document.createDocumentFragment();
// oFra.[add elements];
document.createElement("div").id="myId";
oFra.getElementById("myId"); //not in FF

var oFra = document.createDocumentFragment();
var myDiv = document.createElement("div");
myDiv.id="myId";
oFra.appendChild(myDiv);
oFra.getElementById("myId"); //not in FF

var oFra = document.createDocumentFragment();
var myDiv = document.createElement("div");
myDiv.id = "myId";
oFra.appendChild(myDiv);
if (oFra.hasChildNodes()) {
    var i=0;
    var myEl;
    var children = oFra.childNodes;
    for (var i = 0; i < children.length; i++) {
        if (children[i].id == "myId") {
            myEl = children[i];
        }
    }
}
window.alert(myEl.id);

function Node_getElementById(node, id) {
      for (var i= 0; i<node.childNodes.length; i++) {
          var child= node.childNodes[i];
          if (child.nodeType!==1) // ELEMENT_NODE
              continue;
          if (child.id===id)
              return child;
          child= Node_getElementById(child, id);
          if (child!==null)
              return child;
      }
      return null;
 }

var frag= document.createDocumentFragment();
var mydiv= document.createElement("div");
mydiv.id= 'myId';
frag.appendChild(mydiv);
// keep reference to mydiv

var textblock=document.createElement("p")
textblock.setAttribute("id", "george")
textblock.setAttribute("align", "center")