I have a dropdown menu, two input text box, and a submit button. I want the submit button to be disabled until dropdown item is selected AND both input boxes are filled. I looked at several examples including this one and this one but none of these are working for me. Below is my code. Thanks

<form name=myForm>

  Select an option:

  <select id=dropDown name=dropDown ng-model=data.dropDown >

    ** content for dropDown menu, populating it by using Django

  </select>

  From Date:

  <input type=text id=dateFrom ng-model=data.date1 />

  To Date:

  <input type=text id=dateTo ng-model=data.date2   />



  <button id=submit ng-click=submitRequest() ng-disabled=!(!!data.dropDown && !!data.date1  && !!data.date2)>Submit </button>

</form>

I also tried this method below:

<form name=myForm>

  Select an option:

  <select id=dropDown name=dropDown ng-model=data.dropDown >

    ** content for dropDown menu, populating it by using Django

  </select>

  From Date:

  <input type=text id=dateFrom ng-model=data.date1 required/>

  To Date:

  <input type=text id=dateTo ng-model=data.date2 required />

  <button id=submit ng-click=submitRequest() ng-disabled=myForm.$invalid>Submit </button>

</form>

So initially when the page loads and all fields are empty by default, the Submit button is disabled and the problem is that after all three fields are filled, it doesn't get enabled. Thanks