JSFiddle - React, Tailwind, and code Playground

HTML

<form id='targets' action='http://www.innovativephp.com' method='post'  >
    <input type='text' name='test_field' id='test_field' />
    <input type='submit' value='Save' />
</form>

JavaScript

$('#targets').submit(function() {
   var error=0;
    if ($("#test_field").val()==""){ error=1;}
     if(error){
         alert("Error Occured.Cannot Submit the Form");
         return false;
     }else{
         return true;
     }
 });