Hide register button in checkout page

Is there any way to hide the Register button on the checkout page?

I have tried adding the following lines to the frontend css file but it doesn't remove the button:-
.hikashop_checkout_login_right_part a{
display:none;
}
.hikashop_checkout_login_right_part input{
display:none;
}

Can anyone tell me how to remove the button?

Hi,
Using this kind of CSS code will probably do the job :

#hikashop_register_form_button {
display: none;
}

Thanks that worked.