Registration lookup fields on input length and minimum number of characters

[mkb-buerokonzepte.de]

Hello,

I use Joomla Virtuemart 3.4.1 and 3.0.3.

Now I would like if a user wants to re-up with the VM registration form that they must enter at least 5 characters in the password field and also for example at least 2 numbers.

Also, the user name field should contain at least 3 characters. Where can I find the file for the registration form where I then query this example, can solve using Javascript?

In the edit_adress.php is from line 46, $ this-> vmValidator (); inserted?

Where is the validation javascript file and how I would adapt this to the form fields on input length and minimum character check?

many Thanks