access text inside a button from js

1To get button text inside its tag name

1document.getElementById("myButton2").innnerHTML=
2   "New Button Text using innerHTML";

1document.getElementById("myButton2").childNodes[0].nodeValue=
2   "New Button Text using childNodes";

1ar all = document.getElementsByTagName('*'); 
2for (var i=0, max=all.length; i < max; i++) 
3{
4var elem = all[i];
5if(elem.getAttribute("id") == 'ext-gen26'){
6    if(elem.attributes != null){
7        for (var x = 0; x < elem.attributes.length; x++) {
8            var attrib = elem.attributes[x];
9            alert(attrib.name + " = " + attrib.value);  
10        }
11    }
12}
13};