using System;

using System.Windows.Forms;

namespace LoginFormApp

$\{$

public partial class Form$1$ : Form

$\{$

public Form$1()$

$\{$

InitializeComponent$()$;

$//$ Populate the gender ComboBox

comboBoxGender.Items.Add$("$Male$")$;

comboBoxGender.Items.Add$("$Female$")$;

comboBoxGender.Items.Add$("$Other$")$;

$\}$

private void buttonSubmit$\_$Click$($object sender$,$ EventArgs e$)$

$\{$

$//$ Validate and process the input

string name $=$ textBoxName.Text.Trim$()$;

string surname $=$ textBoxSurname.Text.Trim$()$;

string gender $=$ comboBoxGender.SelectedItem as string;

if $($string$.$IsNullOrEmpty$($name$)||$ string.IsNullOrEmpty$($surname$)||$ string.IsNullOrEmpty$($gender$))$

$\{$

MessageBox.Show$("$Please fill in all fields.", "Error", MessageBoxButtons.OK$,$ MessageBoxIcon.Error$)$;

$\}$

else

$\{$

$//$ Display a welcome message

string welcomeMessage $=$ $"Welcome, $\{$name$\}\{$surname$\}!$ Gender: $\{$gender$\}"$;

MessageBox.Show$($welcomeMessage$,$ "Welcome", MessageBoxButtons.OK$,$ MessageBoxIcon.Information$)$;

$//$ Clear the form after submission

textBoxName.Clear$()$;

textBoxSurname.Clear$()$;

comboBoxGender.SelectedIndex $=-1$;

$\}$

$\}$

$\}$

$\}$ check this code and screenshots needed