one button click with two message boxes with yes no option in javascript

Sorry i think i have not clarified you clearly, how i want it.
1.How first msg box contain both (yes and no) option, i want exactly like that.Means second msg box also contain msg title and both (yes and no) option.Importantly i have to access that second msg confirmation value.(this happening based on onclientclick event))
2.In first msg box, after confirmation i got confirmation value as below:
if(Addflag==1)
string confirmvalue = Request.Form["confirm_value"];//for first msg("are you want to save");
if (confirmvalue== "Yes")
{
con.Close();
con.Open();
sqlcmd2 = new SqlCommand("INSERT INTO city_name(C_name) VALUES('" + txtbox_city.Text + "')", con);
sqlcmd2.ExecuteNonQuery();
txtbox_city.Text = string.Empty;
}
else if (confirmvalue == "No")
{
msg("cancelled");
}
}
3.So now i want like that same confirmation value for second msg box like:
if(Addflag==1)
string confirmvalue = Request.Form["confirm_value"];//for first msg("are you want to save");
if (confirmvalue== "Yes")
{
con.Close();
con.Open();
sqlcmd2 = new SqlCommand("INSERT INTO city_name(C_name) VALUES('" + txtbox_city.Text + "')", con);
sqlcmd2.ExecuteNonQuery();
txtbox_city.Text = string.Empty;
}
else if (confirmvalue == "No")
{
msg("cancelled");
}
}
if (Editflag == 1)
{
string edit_qry = "select * from ledger_details where L_city='" + PrevCname + "'";
con.Close();
con.Open();
sqlcmd2 = new SqlCommand(edit_qry, con);
sqlreader2 = sqlcmd2.ExecuteReader();
if (sqlreader2.HasRows)
{
string confirmvalue = Request.Form["confirm_value"]; //second msg("this record in the main table, are you sure to edit this?.");
if (confirmvalue == "Yes")
{
con.Close();
con.Open();
string edit_update = "Update ledger_details set L_city='" + Cname + "' where L_city='" + PrevCname + "' ";
sqlcmd2 = new SqlCommand(edit_update, con);
sqlcmd2.ExecuteNonQuery();
con.Close();
con.Open();
string edit_update1 = "Update city_name set C_name='" + Cname + "' where C_ID='" + row_id + "'";
sqlcmd2 = new SqlCommand(edit_update1, con);
sqlcmd2.ExecuteNonQuery();
txtbox_city.Text = string.Empty;
}
else
{
message( "You have cancelled to save the city name..");

}
}