Create Discussion Item in Discussions List

createDiscussion.js

function createDiscussion(listTitle,properties,OnItemAdded,OnItemError)
{
    var context = new SP.ClientContext.get_current();
    var web = context.get_web();
 
    var list = web.get_lists().getByTitle(listTitle);
    context.load(list);
    
    var discussionItem = SP.Utilities.Utility.createNewDiscussion(context, list, properties.Subject);
    for(var propName in properties) {
       if(propName == 'Subject') continue; 
       discussionItem.set_item(propName, properties[propName]) 
    }
    discussionItem.update();
    context.load(discussionItem);
    
    context.executeQueryAsync(
        function() {
          OnItemAdded(discussionItem);           
        },
        OnItemError
    );
}