function validate(id){
                $.ajax({url: '/ajax_validation/', 
				 assync: false,
			     data:  { id: $('#'+id).val(),field: id },
                 type: 'POST',
	             success: function(obj){
	                  $('#'+id+'_field_error').replaceWith(obj);
				    },
				 error: function(){
					 $('#'+id+'_field_error').replaceWith('<div style="color:#00FF00">Âñ¸ îê</div>');
				 }

				});
}