If you have to retrieve the label of an attribute in a form script, you have two options. The first one, is of course not supported, but quick and easy to implement.
function GetFieldLabel(fieldname) { var field = crmForm.all[fieldname+ '_c']; if (field != null){ return field.firstChild.firstChild.nodeValue; } else { return ''; } } alert(GetFieldLabel('subject'));
The other option is, to retrieve the label for the user language from the crm service. I will cover this in another article.