function initCompletion(input) {

  input.__completionitems = document.createElement("div");
  input.__completionitems.style.display = "none";
  input.__completionitems.style.borderStyle = "solid";
  input.__completionitems.style.borderWidth = "1px";
  input.__completionitems.style.position = "absolute";

  document.body.appendChild(input.__completionitems);

  input.clearCompletionItems = function () {
    this.__completionitems.innerHTML = "";
    this.__completionitems.style.display = "none";
  }

  input.setCompletionWidth = function(w) {
    input.__completionitems.__width = w;
  }
  
  input.showCompletionItems = function (ary, callback) {

    var x = 0; var y = 0;
    for (var o = this; o ; o = o.offsetParent) {
      x += (o.offsetLeft); y += (o.offsetTop);
    } 

    this.clearCompletionItems();

    var ci = this.__completionitems;
    ci.style.width = (ci.__width ?
		      ci.__width : this.offsetWidth + "px")
    ci.style.top = y + this.offsetHeight + "px";
    ci.style.left = x + "px";
    ci.style.display = "block";

    function __addItem(n) {
      var div = document.createElement("div");
      div.style.cursor = "pointer";
      div.style.fontSize = "75%";
      div.style.backgroundColor = "white";
      
      div.onmouseover = function() {
	this.style.backgroundColor = "#36c";
	this.style.color = "white";
      }

      div.onmouseout = function() {
	this.style.backgroundColor = "white";
	this.style.color = "black";
      }

      div.onclick = function() { callback(n); }
      var ary2 = ary[n].split(/\t/);
      if (ary2.length > 1) {
          var span1 = document.createElement("span");
          span1.style.fontSize = "100%";
          span1.innerHTML = ary2[0]+' ';
          var span2 = document.createElement("span");
          span2.style.fontSize = "80%";
          span2.style.color = "Gray";
          span2.innerHTML = '('+ary2[1]+')';
          div.appendChild(span1);
          div.appendChild(span2);
          ci.appendChild(div);
      }
    }
    for (var i = 0; i < ary.length; ++i)  __addItem(i);
  }

  return input;
}