Javascript snippet to use HTML5 localStorage easily. Supports storing any kind of data. Handles commonly occuring exceptions like localStorage quota being exceeded and browser not supporting localStorage. .

localstorage.js

 /*Javascript snippet to use HTML5 localStorage easily. 
 Properly handles situation like 'localStorage not being supported by the browser' and excedding localSorage quota.
 Supports storing any kind of data */
 
 
 /*key should be String, value can be any Javascript object */
    function writeToLocalStorage(key,value) 
    {
      if(typeof(Storage) == 'undefined')
	     {
	       alert("Your browser doesn't support HTML5 LocalStorage which this site make use of. Some features may not be available. Consider upgrading your browser to the latest version");
		     return false;
	     }
	
	    value = JSON.stringify(value); //serializing non-string data types to string
	
       try
       {
           window.localStorage.setItem(key, value);
       }
       catch (e) 
       {
           if (e == QUOTA_EXCEEDED_ERR) {
              alert('Local storage Quota exceeded! .Clearing localStorage');
              localStorage.clear();
              window.localStorage.setItem(key, value); //Try saving the preference again
              }
       }
       
       return true;
    }
	
 
 
   
   function readFromLocalStorage(key)
   {
     if(typeof(Storage) == 'undefined')
      {
	      //Broswer doesnt support local storage
	      return null;
     }
     
     value = JSON.parse(localStorage.getItem(key));
     return value;
     
   }