Populate multiple drop down list selections and custom text in one text field in a form

[mejones]

Hi there, thank you in advance to anyone who can assist! 

I did see a similar question but I wasn't able to solve my issue with the scripts that were provided on that thread..I have tried writing my own script by I haven't been able to get it right.

I have a text field that populates based on the selections from a list box using the code below:

var v = this.getField("Components").value;

if (typeof v=="object") event.value = v.join(", ");

else event.value = v;

This code works for the multiple selections, but if I enter custom text, it automically disappears when I click out of the box. 

If possible, I need a code that allows for multiple selections as well as the ability to type in and save custom text, with each selection seperated by a comma.

Thank you!