A polyfill for the input placeholder attribute.

placefill.js

/**
 * placefill.js - A polyfill for the placeholder attribute.
 * @author Daniel Golden <danielgolden90@gmail.com>
 */

var $place_holder_inputs = $('input[placeholder]');
var place_holder_text = $('input').attr('placeholder');

// make value attribute of all inputs with placeholder attribute equal to
// value of placeholder attribute
$($place_holder_inputs).each(function () {
    $(this).val($(this).attr('placeholder'));
});

// when input with placeholder attribute is focused on, if
// the value is equal to the placeholder attribute
// then make then empty the value of the input
$('input[placeholder]').focus(function () {
    if($(this).val() == $(this).attr('placeholder')) {
        $(this).val('');
    }
});

// when input with placeholder attribute is blured, if the
// input value is blank then make the input value
// equal to the contents of the placeholder attribute
$('input[placeholder]').blur(function () {
    if($(this).val() == "") {
        $(this).val($(this).attr('placeholder'));
    }
});