Get the Canvas object is [object DispHTMLUnknownElement] type

[linkFly6]

Why get the Canvas object is [object DispHTMLUnknownElement] type, the following code:

var els = doc.getElementsByTagName('canvas');
      for (var i = 0; i < els.length; i++) {
        this.initElement(els[i]); //[object DispHTMLUnknownElement]
      }
}

initElement: function(el) {
     //...
     el.innerHTML = '';//throws an exception under IE8
     //...
}

In the right circumstances, it should be [ object DispHTMLGenericElement ].

Why is this so?TKS

[arv]

What browser is this?

[linkFly6]

Internet explorer 8,I have solved this problem.TKS