Package "eventstudies" and column names

Hi!

I have a question to you. I am conducting event studies by using the package "eventstudies". I have the problem with transforming the list of results "es". I receive as column names only the numbers 1 2 3 4 etc. Instead I need to have as the column name the company name for which this returns were presented in "es". Does someone know the way to achieve it?

Thank you in advance.

Iza