I have created a custom object for an RSVP to an event. I created the VF page and everything looked fine. But when I attempt to use the Save button, nothing happens. It's coded the same as the save button I've been using for Leads from another Site I have established, and I don't understand what's wrong. I'm guessing maybe it's because it's a Custom Object that I'm working with now. Here's the code I am using:

<apex:page showHeader="false" standardController="Marketing_Event__c">
  <apex:pageBlock >
  <apex:image url="https://na2.salesforce.com/servlet/servlet.ImageServer?id=01540000000eAhm&oid=00D3000000067lt&lastMod=1279041445000"/><p/>
  <FONT size="8"><b>You're Invited</b></FONT><p/>
   <FONT size="5">You have been invited to attend the Corporate Sneak Peek on Thursday, November 11th.</FONT> <p/>
   
   <FONT size="4"> Please use the below form to RSVP for this event. <p/></FONT>

    <apex:form >    
   <font size="3"> <b>Name:</b>&nbsp;&nbsp;&nbsp; <apex:inputField value="{!Marketing_Event__c.Contact_Name__c}" /><p/>
    <b>Company Name:</b>&nbsp;&nbsp;&nbsp; <apex:inputField value="{!Marketing_Event__c.Company_Name__c}" /><p/>
    <b>Email:</b>&nbsp;&nbsp;&nbsp; <apex:inputField value="{!Marketing_Event__c.Contact_Email__c}" /><p/>
   <b>Will you be attending the Irvine Sneak Peek?</b>&nbsp;&nbsp;&nbsp; <apex:inputField value="{!Marketing_Event__c.Irvine_Sneak_Peek__c}"/><p/>
    <b>Comments:</b> <br/> <apex:inputField value="{!Marketing_Event__c.Comments__c}"/><p/></font>
    <apex:commandButton action="{!save}" value="RSVP"/>

    
    </apex:form>

  </apex:pageBlock>
</apex:page>

Any help would be greatly appreciated