[geo r.]

Hello
I am receiving an "unreachable code error" in the following:

   if (customer != "I"
                && customer != "R"
                && customer != "C");
            {
                MessageBox.Show("Please Enter I for Industrial, R for Residential, or C for Commercial.");
                txtCustomer.Focus();
                return;
            

I am fairly new to C# and not sure how to continue.
I have tried using "&", "==" and combinations thereof.
Thanks
Geo r.

[Ryano121]

Remove the semi-colon at the end of the if statement

[geo r.]

Thanks
I was looking at it for so long, my eyes just glazed over it

[tlhIn`toq]

You should also make this case independent.
"I" != "i"

if (customer.ToLower() != "i" && // blah blah blah

Also consider what happens when your menu gets 20 items long.
Do you really want this long 20+ item list of 'or' statements? Yuck!
And what if they enter "industrial"? Wouldn't it be nice if the program still handled that as "i"?

string validMenuOptions = "irc";
if (!validMenuOptions.contains(customer[0].ToLower())
{
    // Yell at user for not entering a good value
}

My next thought is that having the textbox and submit button at all is just a pain ugly and very Windows 3.5. Why not put in a ComboBox with a set of valid options? Or a menu in the menubar?