So I have multiple dropdowns on my page and i want to create a method, that if a value is selected in one dropdown, the other dropdown disables, which is no value can be selected in the other dropdown and it becomes grey and vice versa.
MY HTML is :

```
<div id="list1" class="dropdown-check-list" tabindex="1">
      <span class="anchor" onclick="getElements(list1)">Select Months</span>
      <ul id="list1_items" class="items" name="month">
        <li><input type="checkbox" name="month" value="Apr-2021">April </li>
        <li><input type="checkbox" name="month" value="May-2021">May </li>
        <li><input type="checkbox" name="month" value="Jun-2021">June </li>
        <li><input type="checkbox" name="month" value="Jul-2021">July</li>
        <li><input type="checkbox" name="month" value="Aug-2021">August</li>
        <li><input type="checkbox" name="month" value="Sep-2021">September</li>
        <li><input type="checkbox" name="month" value="Oct-2021">October</li>
        <li><input type="checkbox" name="month" value="Nov-2021">November</li>
        <li><input type="checkbox" name="month" value="Dec-2021">December</li>
        <li><input type="checkbox" name="month" value="Jan-2021">January </li>
        <li><input type="checkbox" name="month" value="Feb-2021">February</li>
        <li><input type="checkbox" name="month" value="Mar-2021">March </li>
      </ul>
    </div>

    <div id="list2" class="dropdown-check-list" tabindex="100">
      <span class="anchor" onclick="getElements(list2)">Select Quarter</span>
      <ul id="list2_items" class="items" name="quarter">
        <li><input type="checkbox" name="quarter" value="Quarter1">Quarter 1- Apr - Jun</li>
        <li><input type="checkbox" name="quarter" value="Quarter2">Quarter 2- Jul - Sep</li>
        <li><input type="checkbox" name="quarter" value="Quarter3">Quarter 3- Oct - Dec</li>
        <li><input type="checkbox" name="quarter" value="Quarter4">Quarter 4- Jan - Mar </li>
      </ul>
    </div>

```

If someone could please help me.
Thankyou.