Change the status of a panel within a class

In your form

public partial class Form1 : Form
{
Compare cmp = new Compare();
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
hidePanels();
}

public void hidePanels()
{
panel1.Visible = false;
panel2.Visible = false;
panel3.Visible = false;
}

private void button1_Click(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(textBox1.Text) | string.IsNullOrEmpty(textBox2.Text))
{
return;
}
hidePanels();
int a = Convert.ToInt32(textBox1.Text);
int b = Convert.ToInt32(textBox2.Text);
cmp.Comp(a, b, panel1, panel2, panel3);
}

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{

if (e.KeyChar < '0' || e.KeyChar > '9')
{
e.Handled = true;
}

}

private void textBox2_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar < '0' || e.KeyChar > '9')
{
e.Handled = true;
}
}
}

in class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace HiddenPanels
{
class Compare
{

public void Comp(int a, int b, Panel p1, Panel p2, Panel p3)
{


if (a < b)
{
p1.Visible = true;
}
else if (a > b)
{
p2.Visible = true;
}
else
{
p3.Visible = true;
}

}
}
}