Using OnFocus / OnBlur Event On Input Box

I want to have a function on an event
<span id= "nameheader"> </span>
<form method ="post" action="send.php">
<input
id = "nameinput"
class = "input"
value = "name"
onfocus = "focus();"
onblur = "blur();"
/>

That is when you focus on the input box the value ' name' gets put above the box and when you focus on something else it goes back to the box.
this is my function
focus(){
document.getElementById('nameheader').innerHTML = 'name';
document.getElementById('nameinput').value = '';
}
And I would obviously do the opposite for onblur event.