I found this answer on another thread..
How to add multiple buttons in Jquery UI dialog box?
Using this syntax, how do you add class to a particular button?<
You Can add class to the button's in Dialog...by
$('#mydialog').dialog({ buttons:{ "send":{ text:'Send', 'class':'save' }, "cancel":{ text:'Cancel', 'class':'cancel' } });
I think this will work for you. and you can find more answers here.