var i = 0;
var j = 0;
var changeElem = 0;
var setElem = 0;
function setDays(changeElem, setElem){
	if(document.forms[0].elements[changeElem].options[2].selected && //Februar
		(document.forms[0].elements[setElem].options[29].selected ||
		 document.forms[0].elements[setElem].options[30].selected ||
		 document.forms[0].elements[setElem].options[31].selected )) {
		j = 28; 
		document.forms[0].elements[setElem].options[j].selected = true;
	}
	if((document.forms[0].elements[changeElem].options[4].selected ||  //April
		document.forms[0].elements[changeElem].options[6].selected ||  //Juni
		document.forms[0].elements[changeElem].options[9].selected)&&  //September
		document.forms[0].elements[setElem].options[31].selected) { 
		j = 30; 
		document.forms[0].elements[setElem].options[j].selected = true;
	}
}