Error: Button Click Is Undefined - Simple If Statement With Sql Command Wont Work (c#)

hello it seems lack of c# skills is getting the better of me here...iv been trying to get this to work for hours now without success. I have just started working in c# so i am a beginner :)

all i want to do it query the database, check to see if a title exists, if yes then populate textbox saying 'title in use' but if the title doesnt exists then continue executing rest of code to add the title.

You'll notice iv tried to use string variables and sqlDataAdapter but i cant get these to work either...please help

so far i have this that keeps giving me the error that my button click is undefined: protected void bookButton_Click(object sender, EventArgs e){

//string title;try{SqlConnection conn1 = new SqlConnection();

conn1.ConnectionString =

"Data Source=Gemma-PC\SQLEXPRESS;" +"Initial Catalog=SoSym;" +

"Integrated Security=SSPI;";SqlCommand findTitle = new SqlCommand("SELECT title FROM Publication WHERE title='" + titleTextBox.Text + "';", conn1);

 

conn1.Open();

findTitle.ExecuteNonQuery();

 /*

DataSet myDataSetTitle = new DataSet("PublicationTitle");

myDataSetTitle.Clear();

myDataAdapterTitle.Fill(myDataSetTitle);//myDataSet contains results from above SELECT statement

title = myDataSetTitle.Tables[0].Rows[0]["title"].ToString();*/

}catch(Exception ex)

{TitleInvalidMessage.Text = "Title Not Accepted: This title is already in use by another publication" +ex.Message;

}

//title does not exist in table so continue and add to database

//rest of code here