How do i write the user input from my form into text file

Question

i want the text file created by this code to send to server by using mail as i provided email code in my CS file

i used following code but its not enough

 

using (StreamWriter sw = new StreamWriter(@"D:\text.txt"))

{
sw.WriteLine("Name = " + txt_name.Text);
sw.WriteLine("Address = " + txt_ContctNo.Text);

}

 

using this it doesnt create new text file .manually u have to create it first