Can't get it to work with custom form (Toolest CRED)

I’m working with Toolset and there form-generator CRED. They offer Googles reCaptcha, but I wanna give Zero Spam a try. On your installation-page, you are writing of two steps for Zero Spam integration in other plugins. I already have given my form the class-name “zerospam”. But am stucking in how to call your function before the CRED-form-validation-function. Please for a little hint.

Is there a way to shoot your function on form-submit in javascript, like:

jQuery(‘.cred-form’).on(‘submit’, function(ev){
ev.preventDefault();
// zero-spam-validation-function
if ( zerospam_is_valid() ) {
// CRED-form-validation
jQuery(this).unbind(‘submit’).submit();
} else {
zerospam_log_spam( ‘My CRED-Form’, ‘https://www.myurl.com/custom-form’ );
};
});

Please for help!

https://www.ads-software.com/plugins/zero-spam/