Is it possible to create a popup error message if one field does not equal another field?

Is it possible to create an error message to ensure that one field is equal to another field?  I would like my total reservation count to equal meal selections.  I have the fields and calculations, but how do I prevent a reservation being submitted if the two fields are not equal.  I looked at conditions HIDE/SHOW or ENABLE, but the form can still be submitted.

https://form.jotform.com/61175755289972

My thought is that if the two fields are not equal, then a popup message would appear and the user would not be able to submit the form.

Thanks,

You are note able to create a pop up window, but using condition you may hide the submit button so the user will not be able to submit the form unless he correct the error.

You may create a similar condition as below.

Please let us know if this helps.