function form_date_calendar_request(container_id, field_id, month, year, lang, cal_id, cal_class, sd, df, ds) {
      var params = '';
      var q = true;
      if (field_id != undefined) {
         params = params + (q ? '?' : '&') + 'field_id=' + field_id;
	 q = false;
      }
      if (month != undefined) {
         params = params + (q ? '?' : '&') + 'm=' + month;
	 q = false;
      }
      if (year != undefined) {
         params = params + (q ? '?' : '&') + 'y=' + year;
	 q = false;
      }
      if (lang != undefined) {
         params = params + (q ? '?' : '&') + 'lang=' + lang;
	 q = false;
      }
      if (cal_id != undefined) {
         params = params + (q ? '?' : '&') + 'cal_id=' + cal_id;
	 q = false;
      }
      if (cal_class != undefined) {
         params = params + (q ? '?' : '&') + 'cal_cls=' + cal_class;
	 q = false;
      }
      if (sd != undefined) {
         params = params + (q ? '?' : '&') + 'sd=' + sd;
	 q = false;
      }
      if (df != undefined) {
         params = params + (q ? '?' : '&') + 'df=' + df;
	 q = false;
      }
      if (ds != undefined) {
         params = params + (q ? '?' : '&') + 'ds=' + ds;
	 q = false;
      }
      url = '/_xhr/form_date_calendar/' + params;
      xhr_request(xhr_fill_element_quiet, url, container_id);
   }


   function form_date_get_value(field_id, suffix) {
      var field_element = document.getElementById(field_id + '_' + suffix);
      if (field_element != null) {
         return field_element.value;
      } else {
         return false;
      }
   }
   
   function form_date_calendar_refresh(cal_id, field_id, lang, cal_class, sd, df, ds, offset) {
      var day   = parseInt(form_date_get_value(field_id, 'day'));
      var month = parseInt(form_date_get_value(field_id, 'month'));
      var year  = parseInt(form_date_get_value(field_id, 'year'));
      var maxday = 0;
      switch(offset) {
         case '+1':
            month++;
            if (month == 13) {
               month = 1;
	       year++;
            } 
	    break;
	 case '-1':
            month--;
            if (month == 0) {
               month = 12;
	       year--;
            } 
	    break;
      }
      switch(month) {
         case 1:
	 case 3:
	 case 5:
	 case 7:
	 case 8:
	 case 10:
	 case 12:
	    maxday = 31;
	    break;
	 case 4:
	 case 6:
	 case 9:
	 case 11:
	    maxday = 30;
	    break;
	 case 2:
	    maxday = 29;
	    break;
      }
      if (day > maxday && maxday > 0) {
         day = maxday;
      }
      if (day !== false && month !== false && year !== false) {
         form_date_calendar_request(cal_id + '-container', field_id, month, year, lang, cal_id, cal_class, sd, df, ds);
	 form_date_set_value(field_id, day, month, year);
      }
   }

   function form_date_set_value(field_id, day, month, year) {
      day_element = document.getElementById(field_id + '_day');
      month_element = document.getElementById(field_id + '_month');
      year_element = document.getElementById(field_id + '_year');
      
      if (day_element != null) {
         day_element.value = day;
      }
      if (month_element != null) {
         month_element.value = month;
      }
      if (year_element != null) {
         year_element.value = year;
      }
   }


   function form_urlify_string(src) {

      str = src.toLowerCase();
      str = str.replace(/ą/g, 'a');
      str = str.replace(/ć/g, 'c');
      str = str.replace(/ę/g, 'e');
      str = str.replace(/ł/g, 'l');
      str = str.replace(/ń/g, 'n');
      str = str.replace(/ó/g, 'o');
      str = str.replace(/ś/g, 's');
      str = str.replace(/ż/g, 'z');
      str = str.replace(/ź/g, 'z');

      str = str.replace(/[^a-z0-9]/g, '-');
      
      return str;
   }

   function form_urlify(src_id, tgt_id) {
      var src = document.getElementById(src_id);
      var tgt = document.getElementById(tgt_id);
      
      if (tgt.value == '') {
         tgt.value = form_urlify_string(src.value);
      }
   }
   
   function form_checkificate(form_id, input_name, check) {
      var form = document.getElementById(form_id);
      var inputs = form.getElementsByTagName("input");
      for (var i = 0; i < inputs.length; i++) {
         var input = inputs.item(i);
	 if (input.getAttribute("name") == input_name) {
	    if (check) {
	       input.setAttribute("checked", "checked");
	    } else {
	       input.setAttribute("checked", null); // for msie...
	       input.removeAttribute("checked");    // for proper browsers...
	    }
	 }
      }
   }
   
   
   function form_clear_radio(form_id, input_name) {
      var form = document.getElementById(form_id);
      var the_radio = form.elements[input_name];
      
      for (var i = 0; i < the_radio.length; i++) {
         if (the_radio[i].checked == true) {
	    the_radio[i].checked = false;
	 }
      }
   }   
   
   function form_gmap_uri_process(gmap_uri, long_id, lat_id, zoom_id) {
   	var latlong_regexp = new RegExp("[^a-z]ll\=([0-9\.]+)\,([0-9\.]+).*?z\=([0-9]+)");
   	var latlong = latlong_regexp.exec(gmap_uri);
   	var lat = latlong[1];
   	var long = latlong[2];
     	var zoom = latlong[3];
     	if (lat != 0 && long != 0) {
     		$('#' + lat_id).val(lat);
     		$('#' + long_id).val(long);
     	}
     	if (zoom > 0) {
     		$('#' + zoom_id).val(zoom);
     	}
   }