Sentence: Enter another valid zipcode in the Excluded Zip codes text area...

[Sureshvemuri]

Is this correct sentence:

Enter another valid zipcode in the Excluded Zip codes text area starting with comma.

Regards,
Suresh

[Mordant]

It doesn't flow terribly well.

Are you trying to say the text area begins with a comma or that the text the person enters should begin with a comma? The sentence makes the first, which seems far less sensible, seem true. I will guess it's the latter, and my recommendation is based on that.

Starting with a comma, enter another valid zip code in the Excluded Zip Codes text area.

"Starting" now connects with the implied subject, "you." The person thus starts with a comma upon entering the zip code.

[Sureshvemuri]

Excellent - You understood it from a lot of confusion.
The second one. You are right.

11112,99876
User first enters the 1st zipcode.
After sometime, should enter the 2nd zipcode starting with comma.

Cheers,
Suresh