if ($('html').is('.m320, .m768')) { ... }
//https://stackoverflow.com/questions/10559153/jquery-hasclass-for-multiple-values-in-an-if-statement
var $html = $("html");
if ($html.hasClass('m320') || $html.hasClass('m768')) {
// do stuff
// https://stackoverflow.com/questions/10559153/jquery-hasclass-for-multiple-values-in-an-if-statement
}
$('span').is(".foo.me"); // AND logic