var agt=navigator.userAgent.toLowerCase();
    var is_ie     = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
    var is_win    = ((agt.indexOf("win")!=-1) || (agt.indexOf("16bit")!=-1) );
    var is_mac    = (agt.indexOf("mac")!=-1);
    var is_opera  = (agt.indexOf("opera") != -1);
    var is_konq   = (agt.indexOf("konquer") != -1);

//SCRIPT OM BROWSERAFHANKELIJK CSS TE BEPALEN
    if (is_ie) {
      var oHEAD=document.getElementsByTagName('HEAD').item(0);
      var nLink=document.createElement('LINK');
      nLink.rel="stylesheet";
      nLink.type="text/css";

      if (is_win) {
       var nCss2Style=document.getElementsByTagName('STYLE').item(1);
       nLink.href="layout/layout_ie_pc.css";
       oHEAD.replaceChild(nLink,nCss2Style);
      } else if (is_mac) {
       nLink.href="layout/layout_ie_mac.css";
       document.styleSheets[1].disabled = true;
       document.write('<link rel="'+nLink.rel+'" type="'+nLink.type+'" href="'+nLink.href+'" />');
      }
    }

//SCRIPT VOOR HET OPENEN VAN NIEUW VENSTER MET EEN NIEUWE HTMLPAGINA
    function wopen(obj, w, h)
    {
      if(!w) { w = 800; }
      if(!h) { h = 600; }
      winoptions="height="+h+",width="+w+",,"+
                 ",menubar=no,resizable=yes,scrollbars=yes,status=no,titlebar=no,toolbar=no";
      win=window.open("","info",winoptions);
      win.location.href=obj.href;
      if (parseInt(navigator.appVersion) >= 4)
                    { win.window.focus(); }
      return false;
    }

//SCRIPT  OM BUTTONS IN DIVERSE NAVIGATIEITEMS TE ACTIVEREN        
function setNav() {

        if (document.getElementById("subnavigatie")) {
            subnavsrc = document.getElementsByTagName("h1");
            if( subnavsrc[0] && subnavsrc[0].getAttribute('id') ) {
                axis = subnavsrc[0].getAttribute('id');
                axis_arr = axis.split( '-' );
                for (cnt=0; cnt<axis_arr.length; cnt++) {
                    prefix = 'sub';
                    prefix += cnt>0 ? 'sub' : '';
                    prefix += cnt>1 ? 'sub' : '';
                    if (document.getElementById(prefix+'-'+axis_arr[cnt])) {
                        if (document.getElementById('ul'+prefix+'-'+axis_arr[cnt])) {
                            document.getElementById('ul'+prefix+'-'+axis_arr[cnt]).style.visibility = 'visible';
                            document.getElementById('ul'+prefix+'-'+axis_arr[cnt]).style.display    = 'block';
                        }
                        document.getElementById(prefix+'-'+axis_arr[cnt]).className = 'activated';
                    }
                }
            }
        }
    }        

function setHeight ()
    {
        subMarPad = 220; /* the total value of margins and padding to subtract from the body height */
        mainDiv = document.getElementById('iemaccontainer');
        mainDiv.style.top = (parseInt(document.body.clientHeight)/2 - subMarPad) + "px";
        mainDiv.style.visibility = "visible";
    }
	
//MAILSCRIPT & VALIDATIE

function init_forms(){
	var forms = document.getElementsByTagName("form");

	for(n=0; n<forms.length; n++){
		var form = forms[n];
		form.onsubmit = form_submit;
	}
}

function form_submit(){
	this.valid = true;
	
	var elems = this.elements;
	for(n=0; n<elems.length && this.valid; n++){
		elem = elems[n];
		var validation = elem.getAttribute("required");
		if(validation != null){
			switch(validation){
				case "true":
					if(elem.value.trim().length == 0){
						this.valid = false;
						elem.select();
						elem.className += " invalid";
					}
					else{
						elem.className =  elem.className.replace(/invalid/g ,"");
					}
					break;
	
				case "email":
					if(is_email(elem.value)){
						this.valid = false;
						elem.select();
						elem.className += " invalid";
					}
					else{
						elem.className =  elem.className.replace(/invalid/g ,"");
					}
					break;
	
				default:
					if(test = elem.form.elements[validation]){
						if(test.value != elem.value){
							this.valid = false;
							elem.select();
							elem.className += " invalid";
						}
						else{
							elem.className =  elem.className.replace(/invalid/g ,"");
						}
					}
					break;
				
			}
		}
	}

	return this.valid;
}


function is_email(email){
	var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
	var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$");
	return ! (!r1.test(email) && r2.test(email));	
}

String.prototype.trim = function() { return this.replace(/^\s+|\s+$/, ''); };

function doInit () {
	 if (is_ie && is_mac) { setHeight(); }
    setNav();
	init_forms();
}

window.onload = doInit;