How text is Convert from lower to Upper case in Html

Source Code: Here Enter a any text
Enter your name: (converted into uppercase)

<script>
function u()
 { var a=document.getElementById("name").value document.getElementById("name").value=a.toUpperCase() ;
}

</script>

<p>Entering text is converting into UpperCase</p>

Enter your Name:<input type="text" name="name" id="name" onblur="u()"/>