How specific do you mean? I'm sorry, but I'm not writing the code out for you. We do not provide custom coding here. I can only provide you with suggestions or small examples.
You need 2 actions. The first action will have 2 Code usages in it (see the + button to the far right of the code action). 1 of the Code usages will generate your number, send it as SMS, then store it to their profile. The next Code usage will be your HTML form. There's a Method parameter to determine what type of code the Code action is (e.g. PHP, HTML, etc..). The second action is what your <form action URL will be and is where you'll validate the form submit to ensure the code is right. Example as follows.
Global
Triggers: None
Type: Code
User: Automatic
Access: Everybody
Action
Code 1: (Method PHP)
Code:
$SMScode = rand();
// SEND SMS HERE
$user->set( 'cb_phoneverificationcode', $SMScode );
$user->store();
Code 2: (Method HTML)
Your form would submit to the below action. You can use whatever action you want below. Could be a redirect, another code action, etc.. just depends on what you want to do. The validation is handled by the conditional and if the condition passes the action will execute. Otherwise it'll just fail and display nothing, which you could have a 3rd action that and have the form fire both of them by using &actions=ACTION_ID_1,ACTION_ID_2 in the URL to handle a case where the code doesn't match.
Global
Triggers: None
Type: ANY
User: Automatic
Access: Everybody
Conditional
[cb_phoneverificationcode] Equal To [post_veficationcode]
krileon
