// from snipplr.com code snippets
// http://snipplr.com/view/28115/getelementsbyattribute/
// Derivative from Dustin Diaz's getElementsByClass

document.getElementsByAttribute = function( attrib, value, context_node, tag ) {
    var nodes = [];
    if ( context_node == null )
        context_node = this;
    if ( tag == null ) 
        tag = '*';
    var elems = context_node.getElementsByTagName(tag);
    
    for ( var i = 0; i < elems.length; i += 1 ) {
        if ( value ) {
            if ( elems[i].hasAttribute(attrib) && elems[i].getAttribute(attrib) == value )
                nodes.push(elems[i]);
        } else {
            if ( elems[i].hasAttribute(attrib) )
                nodes.push(elems[i]);
        }
    }
    return nodes;
}