Error message while updating Person Account through visual force wizard

 herei s my code 

<apex:page controller="patientController" tabStyle="Opportunity" sidebar="false" showHeader="false">
<apex:form >
<apex:pageBlock title="Record Type">
<apex:pageMessages />
<apex:pageblocksection >
<apex:panelGrid >
<apex:outputLabel value="Record Type" for="recordtype"/>
<apex:inputField id="recordtype" value="{!PersonAccount.RecordTypeId}"/>

</apex:panelGrid>
</apex:pageblocksection>

<apex:pageBlockSection title="Contact Information">
<apex:panelGrid columns="2">
<apex:outputLabel value="Name" for="perfirstName"/>
<apex:inputField id="perfirstName" value="{!PersonAccount.Name}"/>
</apex:panelGrid>
</apex:pageBlockSection>

<apex:facet name="footer">
<apex:outputPanel >
<apex:commandButton action="{!step1}" value="Next" styleClass="btn"/>
</apex:outputPanel>
</apex:facet>
</apex:pageBlock>
</apex:form>
</apex:page>

Class.patientController.save: line 70, column 1     

while inserting the Person account error is 

System.DmlException: Insert failed. First exception on row 0; first error: INVALID_FIELD_FOR_INSERT_UPDATE, Account: bad field names on insert/update call: Name: [Name]

Any one please need a suggestion 

 public PageReference save() {   

PersonAccount.RecordTypeId=PersonAccount.RecordTypeId;
insert PersonAccount;

PageReference orderPage = new PageReference('/' +PersonAccount.id);
orderPage.setRedirect(true);

return orderPage;
}

Thanks In advance,

Newbie @ knight12