a = (fix[a] && fix[a].replace && fix[a]) || a;
var r = new RegExp("-([a-z])","ig");
a = a.replace(r,function(z,b){return b.toUpperCase();});
- if ( v !== null ) {
+ if ( typeof v != 'undefined' ) {
o[a] = v;
if ( o.setAttribute ) {
o.setAttribute(a,v);