即使在使用javascript在wordpress中单击“确定”后，如何停止进入下一个POP框？

Question

我有一个可以在下图中显示的表格：

现在，当我没有单击任何复选框时，显示错误请选择一个选项，但是当我单击确定按钮时，它将继续其他弹出表单。我想保留在同一弹出页面上。我的弹出表单代码：

function valthisform()
     {
         var checkboxes = document.querySelectorAll('input[type="checkbox"]');
         var checkedOne = Array.prototype.slice.call(checkboxes).some(x => x.checked);
         if (checkedOne == true)
         {

         } 
         else 
         {
            alert ("Kindly select at least one option !")
form.reload();
         }
     }  

<form name="myform">
<div id="outer-container">
      <label class="ac-service">
          Choose Your Service
      </label>
      <br>
      <hr/>
     <label id="l-1"><input type="checkbox" id="c1" name="checkboxes">AC Not Cooling Properly/Repair</label>
      <ul class="u">
          <li>Complete Diagnosis</li>
          <li>Final Charges Based on Inspection</li>
      </ul>
      <hr/>
       
     <label id="l-1"><input type="checkbox" id="c1" name="checkboxes">Wet Servicing</label>
      <ul class="u">
          <li>Deep Cleaning the AC for fresh air</li>
          <li>Filter, coils etc. cleaned with water</li>
          <li>Save upto 20% on your summer electricity bill with regular servicing </li>
      </ul>
      <hr/>
       
      <label id="l-1"><input type="checkbox" id="c1" name="checkboxes">Installation</label>
      <ul class="u">
          <li>Parts & wall modification charges extra</li>
      </ul>
      <hr/>
      
     <label id="l-1"><input type="checkbox" id="c1" name="checkboxes">Uninstallation</label>
     <hr/>
       
     <label id="l-1"><input type="checkbox" id="c1" name="checkboxes">Gas Charging</label>
      <ul class="u">
          <li>Complete vacuuming and gas filing</li>
          <li>Partial gas refilling/top-up is not recommended</li>
           <li>Minor leakages will be fixed</li>
           <li>Leakage check with Nitrogen is not included</li>
      </ul>
      <hr/>
<input type="button" id="fixed-button" onclick="return valthisform(this.form);" value="Next" class="popmake-391">
</div>
</form>

我正在使用popup maker在wordpress中创建弹出窗口，并与form 7联系以创建表单。

谢谢！