var default_lb = 'Username';
 var lb = document.getElementById('username');
 lb.value = default_lb;
 lb.onfocus = function()
 {
    if(lb.value == default_lb)
    {
       lb.value = '';
    }
 }
 lb.onblur = function()
 {
    if(lb.value == '')
    {
       lb.value = default_lb;
    }
 }
 
 var default_bl = 'Password';
 var bl = document.getElementById('password');
 bl.value = default_bl;
 bl.onfocus = function()
 {
    if(bl.value == default_bl)
    {
       bl.value = '';
    }
 }
 bl.onblur = function()
 {
    if(bl.value == '')
    {
       bl.value = default_bl;
    }
 }