[devote]

document.getElementsByClassName = document.getElementsByClassName || function( className ) {

    var atElem = this && this.nodeType && this || document,
        elems = atElem.getElementsByTagName( '*' ),
        result = [], elem;

    for( var i = 0; elem = elems[ i++ ]; ) {

        if ( elem.className && ( (" " + elem.className + " ").indexOf( " " + className + " " ) >= 0 ) ) {
            result[ result.length ] = elem;
        }

    }

    return result;
}