New-Harddisk help

Hello,

I am looking to add the additional hard disk option when create a new VM. I have used the below

$addition = Read-Host "Y/N"

If ($addition -eq "Y") {

$disk2 = Read-Host etc...} # enter amount in GB for additional disk

otherwise if "n" it will just continue.

For the New-VM part of the script, i have added the same as the above

If ($addition -eq "Y") {

New-HardDisk -VM

What would be the correct parameters to create a basic additional disk as im not sure how much it needs, and is there a better way to do this?

Thanks