I have alltel. And everytime i try and listen to my voicemails, it asks for a security code. And everytime i type in possible codes it says invalid option. I really want to listen to my voicemails. HELP

Some variation on this with each wireless service provider (I have had 4 in the past 9 yrs).
Dial your own phone number from your cellphone.
when asked to enter your security code - enter 0000
then - you will be asked to change your security code....
Once done, you will now just dial your number from your phone, then enter your new security code.

That should do it (for Verizon, Alltell, AT&T, etc.)

the security code could possibly be the last four numbers of your cellphone number

I can help you solve this dilemma, but I will need to know what type of Stratagy Voicemail you have to be 100% sure.

Here's a procedure that may work for ya, if it doesn't just let me know which VM you have and we'll get you setup.

Dial Voicemail (usually 100), when you hear the greeting press the * key. When it asks for your User ID, dial 999. When it asks for the security code, try 999 or 999997. Once logged in press 8 for system functions. After that, listen to the prompts and it should walk you the rest of the way through it.

You are going to have to do a factory reset on it. You will lose all the stuff you had

program a speed dial key with your mailbox number, a pause then your security code.By pressing the speed dial key it will dial up your voicemail box and automatically dial your security code.

If your wife never reset the codes when she used the phone, the "unlock" 4 digit PIN code is usually 1234, or sometimes the service provider resets it to the last 4 digits of your cell phone's number before sending it to you.
The SECURITY code is a 6 digit code which is set to "000000" when the phone is first sent to you and since your wife never used it that should still be it. I'd try entering 000000 for the "invalid security code" message you are getting and see if that does it. Some service providers may reset that security code before sending the phone to you too, so if any of those codes don't work you'll have to call your cell phone service provider to find out the codes. This info about all the codes was in my Razr V3 manual. Hope it helps.  If that does work for you and you can get into voicemail, then to reset the codes to your own personal ones go to ....Settings > Security > New Passwords and reset them.
If you get to the voicemail message screen and the message  stored there, (it's probably a message from the service provider) you have to call the voicemail number to retrieve the message, I just  press the keypad "dot" on the top right side under where it will say "call " and it dials & brings me to my voicemail.  The voicemail number should be stored in the phone, but because it was never set up you may have to call the provider to do so, I can't remember if it was already in there or not when I first set my phone up. Anyways......Good Luck & Happy New Year ; )

Knowing what type of System and Voicemail you have would be beneficial to know. This may work for you, if it doesn't just let me know which VM you have and we'll get you setup.

Dial Voicemail (usually 100), when you hear the greeting press the * key. When it asks for your User ID, dial 999. When it asks for the security code, try 999 or 999997. Once logged in press 8 for system functions. After that, listen to the prompts and it should walk you the rest of the way through it.

try 12345

Call service provider, they can reset your voicemail options.

Find out who has administrator access (usually extension 100) and use that phone, call voicemail, press "more" press "MGR" press "CHBX" listen to the voicemail which will prompt/ask you if you want to delete the security code. Say yes!