Prevent number values in short text fields

I need a simple way to prevent responses in "short text" field are submitted as "alphabetic characters" only. I tried the "Validation" feature but when I tested the form, it still allowed numbers to be typed. How can this be fixed?
Note: Using the "Masking" feature won't work because I'm not looking for a specific response.
Please help. Thanks!

Hi Geta,

Thanks for reaching out to Jotform Support. I checked your form and it seems that the Alphabetic Validation is working:

I have cleared your form cache, please try checking again.

Let us know if you have any other questions.