Can't access global variables inside Handlebars helpers

Question

hbs.registerHelper('for', function(from, to, incr, block) {
  var accum = '';
  for(var i = from; i < to; i += incr)
      accum += block.fn(i);
  return accum;
});

{{#for dataobj.pagelow dataobj.pageup 1}}
    <li class="page-item"><a class="page-link" href="{{url}}/{{this}}">{{this}}</a></li>
{{/for}} 

I can't access {{url}} which i passed at render time. what i am missing in this code. please help me out.

Thanks Shah