title: Unable to clear the fileds after saving the data using apex code
body: <pre><code>//Apex page
   &lt;apex:page controller="MyController" tabStyle="Account"  showChat="false" &gt;
      &lt;apex:form &gt;
          &lt;apex:pageBlock title="Congratulations  {!$User.FirstName}"&gt;
              You belong to Account Name: &lt;apex:inputField value="{!account.name}"/&gt;
            Annual Revenue:  &lt;apex:inputField value="{!account.AnnualRevenue}" required="true"/&gt;
             &lt;apex:commandButton action="{!save}" value="save"/&gt;&lt;/apex:pageblock&gt;
      &lt;/apex:form&gt;
  &lt;/apex:page&gt;
  </code></pre>
  
  <p>My code is saving the data to my account successfully.But,the fields are not clearing until i press refresh button   </p>
  
  <pre><code>//Apex Class
  
  public class MyController {
  
  
      private Account account; public Account getAccount(){
      if(account == null)
      account=new Account();
      return account;
      }
      public PageReference save(){
      insert account;
      return null;
      }
  }
  
  My code is saving the data to my account successfully.But,the fields are not clearing until i press refresh button. 
  
  So, anyone can guide me to clear the page after saving my data?
  </code></pre>