function openMailClient(){
	head = 'mailto:mail';
	tail = 'design-goettlich.de';
	document.location.href = head + '@' + tail;
}

function switchBackground(tagID,max){
	tag = $('#'+tagID);
	str = tag.css('background-image');
	head = str.substr(0,str.lastIndexOf('.'));
	tail =  str.substr(str.lastIndexOf('.'));
	num = head.substr(head.length - 2, 2);
	count = parseInt(num,10);
	if (isNaN(count)) {
		if (max > 0) back = head + '_01' + tail;
		else return;
	} else {
		head = head.substr(0,head.length - 3);
		if (count < max){
			count++;
			
			num = ((count < 10)?'0':'')+count;
			
			back = head + '_' + num + tail;
		} else {
			back = head + tail;
		}
	}
	tag.css('background-image',back);
}