function popup(file, width, height) { 
  window.open(file , '', 'resizable=1,location=0,directories=0,status=0,menubar=0,scrollbars=0,toolbar=0,'+
                         'width='+width+',height='+height); 
}


function goto(target) {
	window.location.href = target;
}	


function set(el, state, urlPrefix) {
    
    if(state == "on") {
        chgImg(el, urlPrefix + 'img/btn-subnav-on.png');
    } else {
        chgImg(el, urlPrefix + 'img/btn-subnav.png');
    }
}


function _get(id) {
    return document.getElementById(id);
}


function setVis(layerName, visible) {
    objLayer = _get(layerName);
    if(document.layers){
        objLayer.visibility  = (visible == true) ? 'show' : 'hide';
    } else {
        objLayer.style.visibility = (visible == true) ? 'visible' : 'hidden';
    }
}


function chgVis(layerName) {
    objLayer = _get(layerName);
    if(document.layers){
        if(objLayer.visibility == 'show')
            objLayer.visibility = 'hide';
        else
            objLayer.visibility = 'show';
    } else {
        if(objLayer.style.visibility == 'visible')
            objLayer.style.visibility = 'hidden';
        else
            objLayer.style.visibility = 'visible';
    }
}


function chgImg(ele, newUrl) {
    if(typeof(ele) == "string") {
        ele = document.getElementById(ele);
    }
    document[ele.name].src = newUrl;
}


function chgClass(ele, className) {
   var obj;
   if(typeof(ele) != "object") {
      obj = document.getElementById(ele);       
   } else {
      obj = ele;
   }
   
   obj.className = className;

}