commandButton to commandLink in a login form

Question

This is my xhtml login page ...

<div id="externalborderReg">
    <p:spacer height="70px" />
    <div id="loginForm" >
       <h:form id="login" onsubmit="document.getElementById('login').action='j_security_check';" prependId="false">
          <h:panelGrid columns="2">
             <p:outputLabel for="j_username" value="Email:" />
             <p:inputText id="j_username" name="j_username" placeholder="Email" required="true"/>
             <p:outputLabel for="j_password" value="Password:" />
             <p:password id="j_password" name="j_password" placeholder="Password"  required="true" />
          </h:panelGrid>
          <p:spacer height="40px"/>
          <div id="loginButton">
             <p:commandButton id="submit" value="Login" ajax="false" />
          </div>
       </h:form>
    </div>
</div>

Now i want to make the p:commandButton a h:commandLink but if i try change it the login button/link stops working ... how can i cahnge it???

Please help me ...