Update location search parameter

getSearch

/**
 * Get search parameters as an object.
 * Pasing a key will return the givin value
 */
var getSearch = function(key) {
	var search = location.search.trim().slice(1).split('&'),
		params = {};

	// Split search into an paras obj
	while(search.length) {
		var param = search.shift().split('=');

		// Make sure properties has a key
		if(param[0]) {
			params[param[0]] = param[1];
		}
	}

	return key ? params[key] : params;
};

updateSearch

/**
 * Updates a query key, using pushState,
 * without replacing the rest of the query parameters
 */
var updateSearch = function(key, value) {
	if(history.pushState){
		var params = getSearch(),
			query = '';

		// Set the key => val
		params[key] = encodeURIComponent(value);

		// Rebuild search
		for(var param in params) {

			// Only add param if it has a value
			if(params[param]) {
				query += query.length ? '&' : '?';
				query += param + '=' + params[param];
			}
		}

		history.pushState(null, null, query);
	}
};