How to use the unknown. function in unknown

var $formFieldLabel = $('<label>').attr({"for":"pog_"+safeid,"id":"pog_"+safeid+"_id","title":labelTitle}).text(pog.prompt);

	$formFieldDiv.append($formFieldLabel);
	
//Push the new div into a div with id JSONPogDisplay as a new child.
//	var $displayObject = $("#JSONPogDisplay_"+pid);
//	$displayObject.append($formFieldDiv);   /// NOTE the form ID on this should probably be auto-generated from the element ID.

    if (this.handlers["pogid."+pogid]) {
      $optionObj = eval("this."+this.handlers["pogid."+pogid]+"(pog,safeid)");
      }
    else if (this.handlers["type."+pog.type]) {
      $optionObj = eval("this."+this.handlers["type."+pog.type]+"(pog,safeid)");
      }
    else {
      $optionObj = eval("this."+this.handlers["unknown."]+"(pog,safeid)");
      }
	$formFieldDiv.append($optionObj);
	return $formFieldDiv;
  }

</label>

var $formFieldLabel = $('<label>').attr({"title":labelTitle}).addClass("label_"+pog.type).text(pog.prompt);

	$formFieldDiv.append($formFieldLabel);
	
//Push the new div into a div with id JSONPogDisplay as a new child.
//	var $displayObject = $("#JSONPogDisplay_"+pid);
//	$displayObject.append($formFieldDiv);   /// NOTE the form ID on this should probably be auto-generated from the element ID.

    if (this.handlers["pogid."+pogid]) {
      $optionObj = eval("this."+this.handlers["pogid."+pogid]+"(pog)");  // this[this.handlers["pogid."+pogid]](pog)
      }
    else if (this.handlers["type."+pog.type]) {
      $optionObj = eval("this."+this.handlers["type."+pog.type]+"(pog)");
      }
    else {
      $optionObj = eval("this."+this.handlers["unknown."]+"(pog)");
      }
	$formFieldDiv.append($optionObj);
	return $formFieldDiv;
  }
</label>