removeURLParam.js

var removeURLParam = function (url, parameter) {
  var fragment = url.split('#'),
      urlparts= fragment[0].split('?'),
      urlBase = '',
      queryString = '',
      prefix = '',
      pars = null,
      i = 0;

  if (urlparts.length>=2)
  {
    urlBase = urlparts.shift(); //get first part, and remove from array
    queryString = urlparts.join('?'); //join it back up

    prefix = encodeURIComponent(parameter)+'=';
    pars = queryString.split(/[&;]/g);
    for (i= pars.length; i-->0;) {               //reverse iteration as may be destructive
      if (pars[i].lastIndexOf(prefix, 0)!==-1) {   //idiom for string.startsWith
        pars.splice(i, 1);
      }
    }
    url = urlBase+'?'+pars.join('&');
    if (fragment[1]) {
      url += '#' + fragment[1];
    }
  }
  return url;
};