function newUrl( param, value ) {
var queryParameters = {}, queryString = location.search.substring(1), re = /([^&=]+)=([^&]*)/g, m;
while (m = re.exec(queryString)) {
queryParameters[decodeURIComponent(m[1])] = decodeURIComponent(m[2]);
}
queryParameters[ param ] = value;
location.search = $.param(queryParameters);
}