how to delete row delete in grid view (asp.net) backend my sql

protected void lnkdelete_Click(object sender, EventArgs e)
{

LinkButton lnkbtn= sender as LinkButton;
//getting particular row linkbutton
GridViewRow gvrow = lnkbtn.NamingContainer as GridViewRow;
//getting userid of particular row
int userid = Convert.ToInt32(gvrecords.DataKeys[gvrow.RowIndex].Value.ToString());
string username = gvrow.Cells[0].Text;
con.Open();
SqlCommand cmd = new SqlCommand("delete from UserDetails where UserId="+userid,con);
int result=cmd.ExecuteNonQuery();
con.Close();
if (result == 1)
{
BindUserDetails();
//Displaying alert message after successfully deletion of user
ScriptManager.RegisterStartupScript(this, this.GetType(), "alertmessage", "javascript:alert('" + username + " details deleted successfully')", true);
}