Test cases to test data entry field Data Entry Req

Need help to create test case for these senorios:

Create test cases to test data entry field Data Entry Req.
Customer Name: 50 characters, alphanumeric, required.
Streed Address: 25 characters, alphanumeric, required.
City: 25 chracters, alphanumeric, required.
State: 2 chracter drop-down box of state codes, required.
Zip: 5 digits numeric, required.

City, State and zip must be a valid combination (database of valid combinations is assumed OK for this test)

Control Button: New - clear fields, place cursor on customer number field (all field enabled)

[b]Question asked by visitor Rani[/b]

As per your requirement , I can confirm one thing that you are asking for all test cases required to valid submission of your Form, and if I am not wrong, It is customer Profile form.Anyway,

First you have to test each control for valid data(alphanumeric for Customer Name, for example, with limit of 50).
Then do positive testing whether form accept all data or not?
You have not told about mandatory fields, anyway, do negative testing by leaving them blank in possible combinations.

Actually it's the simplest form to test and write test cases, even I will suggest it to freshers and beginners in testing to try test cases for this.Still have any problem, write to me.

apart from the others , one can also test to see if special characters can b entered or not , does the system trim the blank spaces or not,