New Element 'Class' bug in IE 7 and 8

i can't select categories or subcategories if i create a new Content type in ie8 there was always an error: "Expected identifier, string or number"

var li = new Element('li', {id: 'cat'+ id, class: 'default_category'});

the problem is that the word "class" is a reserved keyword in IE

the following code works:

var li = new Element('li', {id: 'cat'+ id, "class": 'default_category'});

i had to change it in:

administrator\components\com_cobalt\views\category\tmpl\edit_relative_cats.php

Line 54,106,109

administrator/component/com_cobalt/views/type/tmpl/edit_limit_cats.php

Line 68, 84, 152, 155, 216, 219

components\com_cobalt\library\php\html\tags.php

Line 391

components\com_cobalt\library\php\html\categories.php

Line 222, 275, 278

Greetings