Apply CSS class to focused element with jQuery
See here for the original answer.
You just have to add separate ID's to access the different fields:
<span class="fakeplaceholder" id="first">First Name</span>
<span class="fakeplaceholder" id="last">Last Name</span>
Then apply the fakeplaceholdertop class to the specific element:
$(".firstname").focus(function() {
$("#first").addClass("fakeplaceholdertop");
});
$(".lastname").focus(function() {
$("#last").addClass("fakeplaceholdertop");
});