function $ (id) {return document.getElementById(id)}

function go (url) {document.location.href=url}

function isEmpty (el) {
  return el.value.match(/^\s*$/)
}

function hl (li) {
  li.className+=(li.className==""?"hover":" hovered")
}

function _hl (li) {
  li.className=li.className.replace(/ ?hovered/,"")
  li.className=li.className.replace(/ ?hover/,"")
}

function changeMonth (scr,month,year) {
  AJAXReq(scr+"ajax/?month="+month+"&year="+year, function(text){
    $("calendar_block").innerHTML=text
  })
  return false
}

function AJAXReq (url,callBack) {
  var x
  try {x=new ActiveXObject("Msxml2.XMLHTTP")}
  catch (e) {
    try {x=new ActiveXObject("Microsoft.XMLHTTP")}
    catch (e) {x=null}
  }
  if (!x && typeof XMLHttpRequest!="undefined") x=new XMLHttpRequest()
  if (!x) return
  x.open("GET", url, true)
  x.onreadystatechange=function(){if((x.readyState==4)&&callBack)callBack(x.responseText)}
  x.send(null)
}