date.js

date.js

// PARSE THE URL
var QueryString = function () {
  // This function is anonymous, is executed immediately and
  // the return value is assigned to QueryString!
  var query_string = {};
  var query = window.location.search.substring(1);
  var vars = query.split("&");
  for (var i=0;i<vars.length;i++) {
    var pair = vars[i].split("=");
      // If first entry with this name
    if (typeof query_string[pair[0]] === "undefined") {
      query_string[pair[0]] = pair[1];
      // If second entry with this name
    } else if (typeof query_string[pair[0]] === "string") {
      var arr = [ query_string[pair[0]], pair[1] ];
      query_string[pair[0]] = arr;
      // If third or later entry with this name
    } else {
      query_string[pair[0]].push(pair[1]);
    }
  }
    return query_string;
} ();
if (QueryString.date !== undefined) {
  // there's a date in the URL
  var datebits = QueryString.date.split('-');
  var datetest = Date.parse(datebits[2], datebits[1] -1, datebits[0]);
  if (!isNaN(datetest)) {
    // it's a valid date!
    var strdate = datebits[2] + '-' + datebits[1] + '-' + datebits[0];
    var datefield = document.getElementById('event-date');
    datefield.setAttribute("value", strdate);
    datefield.setAttribute("readonly", "readonly");
  }
}