How to find list item title internal name?

Hi ,

How to find list item title name?

I loaded two items like below. chkbox1 is loaded properly and i can also perfomed some operations. But coming to "Title" which is not loading for this i want to know internal name of list item title? 

clientContext.load(oListItem,"Title", "chkbox1");       // load items to oListItem
  
     var lstItmTitle = oListItem.get_item("Title");   
      alert('item title:'+lstItmTitle);

Appreciate if anyone solve this.

Thank you.