小编Akh*_*ind的帖子

$(function() {
  function make_alert() {
    var text = $('#text_').val(); //let suppose it as true
    if (true) {
      alert("yes_text");
      return false;
    } else {
      alert("no_text");
      return false;
    }
  }
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form method="post" action="#" onsubmit="return make_alert()">
	<textarea id="text_">
	</textarea>
	<button id="btn_submit" type="submit" name="type" value="create_first">
	Submit
	</button>
</form>

 function myFunction() {
    var x = document.getElementById("demo");
    x.innerHTML = Math.floor((Math.random() * 100) + 1);
 }

<button onclick="myFunction()">Try it</button>
<input type="text" name="demo" id="demo" value="" size="13" disabled="disabled" />