Alert on gridview edit based on permission

Hi,

I have a gridview with edit option at the start of the row. Also I maintain a seperate table called Permission where I maintain user permissions. I have three different types of permissions like Admin, Leads, Programmers. These all three will have access to the gridview.
Except admin if anyone tries to edit the gridview on clicking the edit option, I need to give an alert like This row has important validation and make sure you make proper changes.When I edit, the action with happen on table called Application. The table has a column called
Comments. Also the alert should happen only when they try to edit rows where the Comments column have these values in them.

ManLog datas
Funding Approved
Exported Applications


My try so far:

public bool IsApplicationUser(string userName)
{
    return CheckUser(userName);
}

public static bool CheckUser(string userName)
{
    string CS = ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();
    DataTable dt = new DataTable();
    using (SqlConnection connection = new SqlConnection(CS))
    {
        SqlCommand command = new SqlCommand();
        command.Connection = connection;
        string strquery = "select * from Permissions where AppCode='Nest' and User_Id = '" + userName + "'";
        SqlCommand cmd = new SqlCommand(strquery, connection);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        da.Fill(dt);
    }
    if (dt.Rows.Count >= 1)
        return true;
    else
        return true;
}

protected void Details_RowEditing(object sender, GridViewEditEventArgs e)
{
    string currentUser = HttpContext.Current.Request.LogonUserIdentity.Name;
    string str = ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();
    string[] words = currentUser.Split('\\');
    currentUser = words[1];
    bool appuser = IsApplicationUser(currentUser);

    if (appuser)
    {
        DataSet ds = new DataSet();
        using (SqlConnection connection = new SqlConnection(str))
        {
            SqlCommand command = new SqlCommand();
            command.Connection = connection;
            string strquery = "select Role_Cd from Permissions  where AppCode='Nest' and User_Id = '" + currentUser + "'";
            SqlCommand cmd = new SqlCommand(strquery, connection);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(ds);
        }
        if (ds.Tables[0].Rows[0]["Role_Cd"].ToString().Trim() != "ADMIN")
        {
            Details.EditIndex = e.NewEditIndex;
            BindGrid();
        }
    }       
}

Really appreciate any help on this.