One input placeholder needed

I am using the following code to show the checkout page:
phpecho do_shortcode( '[mp_checkout]' );

Under Billing and Chimmping address, for "Name" fields, "First" and "Last" test was showing below the fields. CSS added to show them inside the fields

Screenshot:
http://take.ms/o9byI

Can these be added as a placeholder? So "First" and "Last" will disappear one input filed is clicked on?