(function($) {
    $.fn.inputClear = function(options){
        var defaults = {
            attr: 'alt'
        };

        var options = $.extend(defaults, options);

        return this.each(function(){
            var obj=$(this);
            var attribute = options.attr;
            obj.attr(attribute,obj.val());
            obj.focus(function(){
                if(obj.attr(attribute)==obj.val()) obj.val('');
            }).blur(function(){
                if(obj.val()=="") obj.val(obj.attr(attribute));
            });
        });
    };
})(jQuery);

//compacted 
(function(b){b.fn.inputClear=function(c){c=b.extend({attr:"alt"},c);return this.each(function(){var a=b(this),d=c.attr;a.attr(d,a.val());a.focus(function(){a.attr(d)==a.val()&&a.val("")}).blur(function(){a.val()==""&&a.val(a.attr(d))})})}})(jQuery);