script tag inside another script tag not working?

I want to load a script inside another script but it is returning an error

code

<script>
     $(document).ready(function () {
         ----------//code for finding the device
       if(device=='mobile'){
       <script src=""></script>
       }else{
       <script src=""></script>
      }
    });
    </script>

Error:

Uncaught SyntaxError: Unexpected token <

I have tried solutions like:

1)

<script>
    ...some other script...
&nbsp;/script>

2)

<script>
   

via midhun k