Restrict number only in input box

 @section('script')

<script type="text/javascript"> 

         function restrictAlphabets(e) {

             var x = e.which || e.keycode;

             if ((x >= 48 && x <= 57))

                 return true;

             else

                 return false;

         }  

</script>

@endsection

onkeypress='return restrictAlphabets(event)'