How to match regexp in a form of a webpage using Selenium IDE

I'm using Selenium IDE as extension of Chrome to test a website form. I'm trying to test the Name field so I:

• Record the test with selenium on the webpage
• Insert the name name
• Stop recording with selenium
• Add a command with verify value
• Add in Value the desired regexp to match: regexp:[a-zA-Z]
• I start the test and i get no matching... Any ideas? Thanks a lot.

Screen of the test: https://imgur.com/5F7GVGq