// verbeterde functie om eerste form-element te selecteren indien aanwezig
function focusFirst() {
	if ((typeof(document.forms[1]) != "undefined")) {
		if ((typeof(document.forms[1].elements[0]) != "undefined")) {
			document.forms[1].elements[0].focus();
		}
	}
}

//functie om pagina te openen via javascript
function go(paginaURL) {
	location.href = paginaURL;
}

// event handling and $-function--------------------------------------------
function $() {
	var elements = new Array();
	for (var i = 0; i < arguments.length; i++) {
		var element = arguments[i];
		if (typeof element == 'string')
			element = document.getElementById(element);
		if (arguments.length == 1)
			return element;
		elements.push(element);
	}
	return elements;
}
function addEvent( obj, type, fn )
{
	if (obj.addEventListener)
		obj.addEventListener( type, fn, false );
	else if (obj.attachEvent)
	{
		obj["e"+type+fn] = fn;
		obj[type+fn] = function() { obj["e"+type+fn]( window.event ); }
		obj.attachEvent( "on"+type, obj[type+fn] );
	}
}
function removeEvent( obj, type, fn )
{
	if (obj.removeEventListener)
		obj.removeEventListener( type, fn, false );
	else if (obj.detachEvent)
	{
		obj.detachEvent( "on"+type, obj[type+fn] );
		obj[type+fn] = null;
		obj["e"+type+fn] = null;
	}
}
function addLoadEvent(func) {
	var oldonload = window.onload;

	if (typeof window.onload != "function") {
		window.onload = func;
	} else {
		window.onload = function () {
			oldonload();
			func();
		}
	}
}

function getElementsByClass(searchClass,node,tag) {
	var classElements = new Array();
	if ( node == null )
		node = document;
	if ( tag == null )
		tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp('(^|\\s)'+searchClass+'(\\s|$)');
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}
// -------------------------------------------------------------------------


// string manipulations ----------------------------------------------------
function Left(str, n){
	if (n <= 0)
	    return "";
	else if (n > String(str).length)
	    return str;
	else
	    return String(str).substring(0,n);
}
function Right(str, n){
    if (n <= 0)
       return "";
    else if (n > String(str).length)
       return str;
    else {
       var iLen = String(str).length;
       return String(str).substring(iLen, iLen - n);
    }
}
function trim(str){   return str.replace(/^\s*|\s*$/g,"");}
// -------------------------------------------------------------------------