You could also use the store library which performs it for you with crossbrowser ability.
example :
// Store current user
store.set('user', { name:'Marcus' })
// Get current user
store.get('user')
// Remove current user
store.remove('user')
// Clear all keys
store.clearAll()
// Loop over all stored values
store.each(function(value, key) {
console.log(key, '==', value)
})