How to update values in textboxes from gridview using ID

Hi all!

How can i update the values in textboxes from gridview using ID(Primary Key).

Below is my gridview code..

here is my update query--

SqlCommand cmd1 = new SqlCommand("Update tblCRUD set values FirstN='" + TextBox1.Text + "',LastN='" + TextBox2.Text + "',Gender='" + gender + "',Address='" + TextBox3.Text + "',Salary='" + TextBox4.Text + "',Jdate='" + TextBox5.Text + "' where EmpID=?, con1");

cmd1.CommandType = CommandType.Text;

if (con1.State == ConnectionState.Closed)

{

con1.Open();

cmd1.ExecuteNonQuery();

clear();

}

how to pass the EmpID value?

Thanks..