Adding multiple emails to a script

Adding multiple emails to a script

Good morning.
I have a small application that on the submit of the form emails to whoever is selected in the record. This script below works great. But I need to send it to multiple emails. I tried to add them and separate them with a comma. But when I try to save the script it gives me an error on line 2. Which is the start of the script.

input.Management.Email
    From     :  zoho.adminuserid 
    Subject  :  "PO Number" 
    Message  :  "<div>Here is your PO number:</div><div><br></div>" + input.PO_number + "<div><br><div>Thanks, Tim</div></div>" 

This one fails and gives the error.

input.Management.Email, tmaxwell@smbystratos.com
    From     :  zoho.adminuserid 
    Subject  :  "PO Number" 
    Message  :  "<div>Here is your PO number:</div><div><br></div>" + input.PO_number + "<div><br><div>Thanks, Tim</div></div>" 

Thanks