Adds placeholder to browsers that don't support it (IE)

placeholder.js

// Adds placeholder to browsers that don't support it (IE)
$(document).ready(function() {
    if(!$.support.placeholder) {
    	var sel = "*[placeholder]";
    	
    	var addPlaceholders = function () {
            if ($(this).attr('placeholder') && $(this).val() == "") {
            	$(this).val($(this).attr('placeholder'));
            	$(this).addClass('placeholder');
            }
    	};
    	
    	$(sel).focus(function () {
    		if ($(this).hasClass('placeholder')) {
            	$(this).val('');
            	$(this).removeClass('placeholder');
            }
    	}).blur(addPlaceholders).each(addPlaceholders);
    	
    	$('form').submit(function () {
            $('.placeholder', this).each(function () {
            	$(this).val('');
            	$(this).removeClass('placeholder');
            });
            return true;
         });
     }
});