[RESOLVED] How to access Form1 controls from another class?

[canavaroski90]

Hi all c#corner forums,
I'm trying to create my class, but I couldn't succeed to work this code. When I run program, newSerial.sendData() in the Form1.Load() (this is my function which is in my own class) works perfectly, but when I clicked the button (you can see the code, I'm calling the same function) program throws "NullReferenceException" error. What is the solution?

namespace robitSeri
{
    
    public partial class Form1 : Form
    {
        public mySerial newSerial;

        private void Form1_Load(object sender, EventArgs e) 
        { 
             mySerial newSerial = new mySerial(this);
             newSerial.sendData();
 
            // THIS WORKS EXCELLENTLY..
         } 
        
         private void button1_Click(object sender, EventArgs e)
         {
                newSerial.sendData();
              // THIS CODE DOES NOT WORK!!!
          }
 
       
    }

    public class mySerial // this class created by me
    {
          private Form1 frm;

         public mySerial(Form1 newFrm)
        {
           this.frm=newFrm;
        }

         public void sendData()
        {
           frm.serialPort1.Write(sth);
        }

     
    }
}