Creating Blog in your application with Share Post feature. (1 small issue)

I have created my own blog in my knack application so my user can share ideas and give feedback. I wanted to create a share feature in the post so user can share a post with other users. To do this.

1) I created a connection field to users with many to many relationship named it as "Share With"

2) In post details, I created a edit with form button and name it as share. And in that form I only have "Share With" field and I make it to open in modal pop-up.

3)Then I created email rule with a custom email and set email to as - "Share with " field.

And done. Now every time someone click on share button and select users from drop-down and click submit button. Email notification goes to all the users he selected.

This whole thing works perfectly fine. I only have one small issue.

Lets say one user shared the post and email was sent to people he selected.

Now when the second person click on the share button he sees the previously added people in the field. Which he can surely delete and start his own list, but some users get confused with this step.

So I want to create a JavaScript code - to trigger auto delete previously filled "share with field" when a user clicks the share button. So he/she only see blank and always start new list.

If anyone can point to towards the right direction on how to do this. I will really appreciate. .