function init(){
	mincontentheight = 400; 
	contentheight = parseInt(document.getElementById('content').offsetHeight);
	referenzheight = contentheight; 
	if(referenzheight<mincontentheight){
		referenzheight = mincontentheight; 
		resizeelement(document.getElementById('content'), referenzheight);
	}
	resizeelement(document.getElementById('cornerleft'), referenzheight);
	resizeelement(document.getElementById('cornerright'), referenzheight);

	correkthight(document.getElementById('cornerleft'), 229, 206);
	correkthight(document.getElementById('cornerright'), 229, 206);

	resizeelement(document.getElementById('content'), document.getElementById('cornerright').offsetHeight);

}

/**
 * ermoeglicht es elemen mit kachelhingrund 'kontrolliert' enden zu lassen  
 * @param {Object} blockobject blockobjekt des kachelhingrund an das nachfolgende element buendig anschliessen soll
 * @param int offset hoehe des hintegrgrundoffests => ab wann der kachelhingrund ansetzt
 * @param int einheit hoehe der kachel
 */
function correkthight(blockobject, offset, einheit){
	if (blockobject.offsetHeight){
		hoehe = parseInt(blockobject.offsetHeight);
		faktorneu = Math.ceil((hoehe-offset)/einheit);
		blockobject.style.height = (einheit * faktorneu + offset) + 'px';
	} 
}

function resizeelement(blockobject, height){
	blockobject.style.height =  height + 'px'
}


function sethiddenvalue(formnum, fieldname, fieldvalue){
	var pathToForm = document.forms[formnum];
	pathToForm = document.forms[formnum];
	pathToForm[fieldname].value = fieldvalue;
}

function changeImgSrc(imgId, newsource){
	var newsource = newsource?newsource:'';
	imgObj = document.getElementById(imgId);
	if (!newsource){
		lowPos = imgObj.src.indexOf('_l');
		if (lowPos!=-1){
			imgObj.src = imgObj.src.replace(/_l/, '_h');
		}
		else{
			imgObj.src = imgObj.src.replace(/_h/, '_l');
		}
	}
	else{
		imgObj.src = newsource; 
	}
}


errorColor = "#990000";
normalColor = "#000000";
function checkForm (num) 
{
	var errorNote = "Bitte fülle die die rot markierten Felder aus!";
	var err = 0;
	var pathToForm = document.forms[num];
	var pflichtfeld = new Array();
	pflichtfeld[0] = /.{3,}/;//Empfänger
	pflichtfeld[1] = /.+@.+\..+/;//Empfänger E-Mail
	pflichtfeld[2] = /.{3,}/;//Absender
	pflichtfeld[3] = /.+@.+\..+/;//Absender E-Mail
	pflichtfeld[4] = /.{3,}/;//Nachricht

	for (var i=0; i<pflichtfeld.length; i++) {
		if (!pflichtfeld[i].test(pathToForm["answer["+i+"]"].value)) {
			document.getElementById("answer_"+i).style.color = errorColor;
			err++;
		} else {
			document.getElementById("answer_"+i).style.color = normalColor;
		}
	}
	
	if (!err) {
		pathToForm.submit();
	} else {
		document.getElementById("errorNote").innerHTML = errorNote;
	}
}

function resetForm (num) 
{
	var pathToForm = document.forms[num];
	for (var i=0; i<pathToForm.length; i++) {
		if (document.getElementById("answer_"+i)) {
			document.getElementById("answer_"+i).style.color = normalColor;
		}
	}
	document.getElementById("errorNote").innerHTML = "";
	pathToForm.reset();
}