Upload = {

    adicionaEvento : function(obj,tipo,funcao){
        if (obj.addEventListener)
            obj.addEventListener(tipo, funcao, true)
        if (obj.attachEvent)
            obj.attachEvent("on"+tipo, funcao)
    },
    
    removeEvento : function(obj,tipo,funcao){
        if (obj.detachEvent) {
            obj.detachEvent( 'on'+tipo, funcao );
        } else {
            obj.removeEventListener( tipo, funcao, false ); }
    },
    
    removeElemento : function(elemento){
        elemento.parentNode.removeChild(elemento);
    },

    criaIframe : function(){
         var iframe = document.createElement("iframe");
         iframe.setAttribute("id","frameUpload");
         iframe.setAttribute("name","frameUpload");
         iframe.setAttribute("width","500");
         iframe.setAttribute("height","500");
         iframe.setAttribute("border","0");
         iframe.setAttribute("style","width: 0; height: 0;border: none;");
         
         return iframe;
    },
    
    iniciaUpload : function(formulario,pg_grava,pasta,id_imagem){
        
        iframe = Upload.criaIframe();
        formulario.parentNode.appendChild(iframe);
        window.frames['frameUpload'].name="frameUpload";
        var loadIFrame = function(){
            Upload.removeEvento(document.getElementById('frameUpload'),'load',loadIFrame);
             
            var obj_iframe = document.getElementById('frameUpload');
            setTimeout(function(){ Upload.removeElemento(obj_iframe)}, 250);
        }
        Upload.adicionaEvento(document.getElementById('frameUpload'),'load',loadIFrame);

        formulario.setAttribute("target","frameUpload");
        formulario.setAttribute("action",pg_grava + '?nome=' + id_imagem + '&pasta=' + pasta);
        formulario.setAttribute("method","post");
        formulario.setAttribute("enctype","multipart/form-data");
        formulario.setAttribute("encoding","multipart/form-data");
        formulario.submit();
    }	

}