如何觸發unpress上使用Javascript

Question

誰能告訴我怎麼一個按鈕來觸發unpress事件的提交按鈕

我做按下按鈕驗證，如果任何字段爲空。我正在阻止導航到第二頁。但驗證後，如果「發件人」或「收件人」字段留空，提交按鈕仍然處於按下狀態。 這裏

 <form action="NewFile.html"> 
      From:<input id="from" type="text" name="From-busstop"> 
      To:<input id= "to" type="text" name="To-busstop"> 
      How do you want to travel?:<Select id="how" name="How"> 
       <option>Minimum Number of Hops</option> 
      <option>Maximum Bus Route Availability</option> 
      <option>Via Terminal Bus Stations Only</option> 
      <option>Direct Routes Only</option> 
      <option>Shortest Distance</option> 
      </Select> 
      <p> 
      <a href="#two" id="submit" data-direction="reverse" data-role="button" data-transition="flip" onClick="loadpage()" 
       >Submit"</a> 
     </p> 
     </form> 
     <script type="text/javascript"> 
     $('#submit').on('click',function(e) { 
      var from = document.getElementById('from').value; 
      var to = document.getElementById('to').value; 
      var how = document.getElementById('how').value; 

      if(from.length < 1) 
      { 
       alert("From bus-stop is empty"); 
       document.getElementById("from").focus(); 
       e.preventDefault(); 
      } 
      else if(to.length < 1) 
      { 
       alert("To bus-stop is empty"); 
       document.getElementById("to").focus(); 
       e.preventDefault(); 
      } 
     }); 
     </script> 

Answer 1

變化

else if(to.length < 1) 

只

if(to.length < 1) 

---

輸入代碼你想要做兩個if條件，不是嗎？

如果是的話，就沒有必要對其他