Adding multiple account records in single save using visualforce page

Adding multiple  records in single save using visualforce page

Apex Class:
---------------
public class addmultiplerecords{
   account a = new account();
   public list<account> acclist{get; set;}
   public addmultiplerecords(){
     acclist = new list<account>();
     acclist.add(a);
  }
  public void addaccount(){
      account acc = new account();
      acclist.add(acc);
  }
  public pagereference saveaccount(){
          insert acclist;
          return null;
  }
}
Visualforce Page:
----------------------
<apex:page controller="addmultiplerecords">
    <apex:form>
       <apex:pageBlock>
          <apex:pageBlockTable value="{!acclist}" var="a">
              <apex:column headerValue="Account Name">
                  <apex:inputField value="{!a.name}"/>
              </apex:column>
               <apex:column headerValue="Account Number">
                  <apex:inputField value="{!a.accountnumber}"/>
              </apex:column>
               <apex:column headerValue="Account Type">
                  <apex:inputField value="{!a.type}"/>
              </apex:column>
               <apex:column headerValue="Account Industry">
                  <apex:inputField value="{!a.industry}"/>
              </apex:column>
          </apex:pageBlockTable>
          <apex:pageBlockButtons>
              <apex:commandButton value="Add one more account" action="{!addaccount}"/>
              <apex:commandButton value="Save Account" action="{!saveaccount}"/>
          </apex:pageBlockButtons>
       </apex:pageBlock>
    </apex:form>
</apex:page>