Javascript show hide

 Javascript show hide and change attribute value on click
<script type="text/javascript">
function uploadform()
{
    var f1=document.getElementById("frm");
    var b1=document.getElementById("btn");
    if(f1.style.display=="none")
    {
        f1.style.display="block";
        b1.setAttribute("value","Hide");
    }
    else
    {
        f1.style.display="none";
        b1.setAttribute("value","Upload");
    }
}
</script>