How can I set a button "Alt" attribute in a dialog modal form?

How can I set a button "Alt" attribute in a dialog modal form?


How can I set a button "Alt" attribute in a dialog modal form?
Follow an example about button "OK" in my dialog modal form:
$("#modalForm").dialog({
bgiframe: true,
autoOpen: false,
modal: true,
buttons: {
Ok: function() ...
...