JSFiddle - React, Tailwind, and code Playground

HTML

<form id="formid">
    <input type="submit" />
</form>

JavaScript

document.getElementById("formid").onsubmit = function(e) {
    var failed = false;
    // do some verifications, if failed then:
    failed = true;
    
    
    if (failed) {
        // don't allow submission
        // newer browsers
        if (e && e.preventDefault) {
            e.preventDefault();
            alert("stopped submit event");
        }
        return false;
    }
};