The two problems are probably pretty much the same: the compiler can't find anything of that exact name: So there are two things to check.
1) Look at your text box closely: is it's name exactly the same as "txtname"? Remember that C# is case sensitive, so "txtname" is not teh same as "txtName" or "Txtname" or "TxtName", and that it won't "invent" vowels, so it isn't the same as "textname" either!
2) If the name is exactly the same, now check the declaration line and make sure it includes the 'Runat="server"' attribute:
<asp:TextBox ID="txtname" runat="server" MaxLength="6"></asp:TextBox>
If that doesn't fix it, then we need more info - like the page as well.
Then do the same for your InsertOnSubmit method: you need to be sure that the class that db.userinfoes represents contains exactly that method name.