i want to show my result on a lable which i want to use in a method of book class

class Book
Form1 newform = new Form1();
public string BookTitle;
public string BookAuthor;
public string PublishDate;
public const string Publisher = "MICROSOFT";

public void GetDetails()
// showing error here cannot implicity string to lable
newform.lbl_view_title = this.BookTitle;
private void btnMain_Click(object sender, EventArgs e)
CSharp.BookTitle = textBox1.Text;
CSharp.BookAuthor = textBox2.Text;
CSharp.PublishDate = textBox3.Text;