ASP.NET

public bool ValidateNewUser(string strAlias, string strFirst, string strLast)
    {

        SqlConnection MyConn = new SqlConnection(ConfigurationSettings.AppSettings["MyOnlineShoppingConnectionString2"]);

        SqlCommand MyCmd = new SqlCommand("sp_CheckForDuplicates", MyConn);

        MyCmd.CommandType = CommandType.StoredProcedure;

        SqlParameter objParam1;
        SqlParameter objParam2;
        SqlParameter objParam3;

        SqlParameter objReturnParam;

        objParam1 = MyCmd.Parameters.Add("@UserName", SqlDbType.VarChar);
        objParam2 = MyCmd.Parameters.Add("@FirstName", SqlDbType.VarChar);
        objParam3 = MyCmd.Parameters.Add("@LastName", SqlDbType.VarChar);
        objReturnParam = MyCmd.Parameters.Add("@Duplicates", SqlDbType.Int);
        objReturnParam.Direction = ParameterDirection.ReturnValue;

        objParam1.Value = strAlias;
        objParam2.Value = strFirst;
        objParam3.Value = strLast;

        try
        {
            if (MyConn.State == ConnectionState.Closed)
            {
                MyConn.Open();
                MyCmd.ExecuteNonQuery();
            }
            if (objReturnParam.Value > 0)
            {
                lblResult.Text = "UserName already exists or you are already a registered user!";
                return false;
            }
            else
            {
                return true;
            }
           MyConn.Close();
        }
        catch (Exception ex)
        {
            lblError.Text = "Error Connecting to Database!";
        }
    }

string str1 = "window.showModalDialog('child.aspx',null,'status:no;dialogWidth:300px;dialogHeight:150px;dialogHide:true;help:no;scroll:no');";<br />
       ScriptManager.RegisterStartupScript(Page, typeof(Page), "", str1, true);

if (!Page.IsPostBack)<br />
        {<br />
             <br />
           // this.Title = "hnihui"; <br />
            //"window.opener.location=window.opener.location;<br />
            string str = "window.close();";<br />
            Button1.Attributes.Add("onclick", str);<br />
}