How to insert data in database using Textboxes

<asp:Button id='btnAdd' style='Z-INDEX: 101; LEFT: 104px; POSITION: absolute; TOP: 168px' 
	runat='server' Text='Add Record'></asp:Button>
<asp:TextBox id='txtFirstName' style='Z-INDEX: 102; LEFT: 168px; POSITION: absolute; TOP: 40px'
	runat='server'></asp:TextBox>
<asp:TextBox id='txtLastName' style='Z-INDEX: 103; LEFT: 168px; POSITION: absolute; TOP: 80px'
	runat='server'></asp:TextBox>
<asp:TextBox id='txtDate' style='Z-INDEX: 104; LEFT: 168px; POSITION: absolute; TOP: 120px' runat='server'></asp:TextBox>
<asp:Label id='Label1' style='Z-INDEX: 105; LEFT: 56px; POSITION: absolute; TOP: 240px' runat='server'></asp:Label>

On Page_Load

VB.NET

if not Page.IsPostBack then
’....
end if

C#

if(!Page.IsPostBack )
{
//...
}

Use namespaces System.Data.SqlClient, System.Data.SqlTypes
On Button Click
VB.NET

Dim sqlStmt As String
Dim conString As String
Dim cn As SqlConnection
Dim cmd As SqlCommand
Dim sqldatenull As SqlDateTime
Try
	sqlStmt = 'insert into Emp (FirstName,LastName,Date) Values (@FirstName,@LastName,@Date)  '
	conString = 'server=localhost;database=Northwind;uid=sa;pwd=;'
	cn = New SqlConnection(conString)
	cmd = New SqlCommand(sqlStmt, cn)

	cmd.Parameters.Add(New SqlParameter('@FirstName', SqlDbType.NVarChar, 11))
	cmd.Parameters.Add(New SqlParameter('@LastName', SqlDbType.NVarChar, 40))
	cmd.Parameters.Add(New SqlParameter('@Date', SqlDbType.DateTime))

	sqldatenull = SqlDateTime.Null

	cmd.Parameters('@FirstName').Value = txtFirstName.Text
	cmd.Parameters('@LastName').Value = txtLastName.Text
	If (txtDate.Text = '') Then
		cmd.Parameters('@Date').Value = sqldatenull
		’cmd.Parameters('@Date').Value = DBNull.Value
	Else
		cmd.Parameters('@Date').Value = DateTime.Parse(txtDate.Text)
	End If
	cn.Open()
	cmd.ExecuteNonQuery()
	Label1.Text = 'Record Inserted Succesfully'

Catch ex As Exception
	Label1.Text = ex.Message
Finally
	cn.Close()
End Try

On Button Click
C#

string  sqlStmt ; 
string  conString ; 
SqlConnection cn =null; 
SqlCommand cmd =null; 
SqlDateTime sqldatenull ; 
try
{
	sqlStmt = 'insert into Employees (FirstName,LastName,HireDate) Values (@FirstName,@LastName,@Date)  ';
	conString = 'server=localhost;database=Northwind;uid=sa;pwd=;';
	cn = new SqlConnection(conString);
	cmd = new SqlCommand(sqlStmt, cn);
	cmd.Parameters.Add(new SqlParameter('@FirstName', SqlDbType.NVarChar, 11));
	cmd.Parameters.Add(new SqlParameter('@LastName', SqlDbType.NVarChar, 40));
	cmd.Parameters.Add(new SqlParameter('@Date', SqlDbType.DateTime));
	sqldatenull = SqlDateTime.Null;
	cmd.Parameters['@FirstName'].Value = txtFirstName.Text;
	cmd.Parameters['@LastName'].Value = txtLastName.Text;
	if (txtDate.Text == '') 
	{
		cmd.Parameters ['@Date'].Value =sqldatenull ;
		//cmd.Parameters['@Date'].Value = DBNull.Value;
	}  
	else
	{
		cmd.Parameters['@Date'].Value = DateTime.Parse(txtDate.Text);
	}
	cn.Open();
	cmd.ExecuteNonQuery();
	Label1.Text = 'Record Inserted Succesfully';
}
catch (Exception ex)
{	
	Label1.Text = ex.Message;
}
finally
{
	cn.Close();
}