Java script Confirm Box

Java script function for confirm box.

function ConfirmationBox()
{
          var result = confirm('Are you sure you want to delete');
          if (result)
          {

              return true;
          }
          else
          {
              return false;
          }
      }

Call java script function in button.

<input type="button" id="Delete" onclick="ConfirmationBox();" class="btn btn-primary btn-lg pull-right" value="Delete"></input>