Help to decide how to draw sequence diagram for mentioned scenario

I have a button on header, when user clicks on it, it would be displaying Searchform(using line 1) and when user enters search criteria, and press Search, the second line will be calling… so I want to design a sequence diagram for this scenario… can anyone suggest how to draw this steps using sequence diagram?

var model = _userNotificationService.Show();
if (model.DialogResult != DialogResult.OK) return
var searchText = model.Firstname;

Hi user,

Thank you for your inquiry. You can post your work and let us comment. We would be happy to share our opinion with you.

Best regards,
Jick Yeung