Simple placeholder js

gistfile1.js

var Placeholder = {
    init: function(selector) {
        if (!this.supportPlaceholder()) {
            $(selector).placeholder();
        }
    },
    supportPlaceholder: function() {
        return 'placeholder' in document.createElement('input');
    }
}

$.fn.placeholder = function() {
  var object = this,
      focus  = function() {
        if (object.val() == object.attr('placeholder')) { object.val(''); }
      },
      blur   = function() {
        if (!$.trim(object.val())) { object.val(object.attr('placeholder')); }
      };

  blur.call(this);
  return this.focus(focus).blur(blur);
}

$(function() {
  Placeholder.init('input[placeholder]');
});