提交iframe页面中的表单

        function getIframeDoc(id){
            var doc;
            if (document.all){//IE
                doc = document.frames[id].document;
            }else{//Firefox    
                doc = document.getElementById(id).contentDocument;
            }
            return doc;
        }
        function submitB(){
            var doc = getIframeDoc("frameUpload");
            doc.getElementById("formUpload").submit();
        }