Why is a semicolon displayed?

Question

HTML

Hello. There was a question with the data which are deduced from the form. I don't understand why there is a comma after the last name.
And so there are 2 aspx forms. On one we enter data, when the OK button is pressed, the data is transferred to another form and displayed. I am attaching screenshots. Thank you in advance.
P.s. I just started learning asp.net, don't judge me too hard =)