function checkForm(fieldObjZipcode, fieldObjCity) {
	var valueZipcode = fieldObjZipcode.value;
	var valueCity = fieldObjCity.value;
	var isValidZipCode = true;
	var isValidCity = true;
	var errorMessageZipcode = '';
	var errorMessageCity = '';
	
	if(! valueZipcode.match(/^\d{2,5}$/)) {
		isValidZipCode = false;
		errorMessageZipcode += 'Bitte geben Sie zwei bis f\u00fcnf Ziffern der PLZ ein (oder aber eine Stadt).';
	}
	if(! valueCity.match(/^[a-zA-ZäÄöÖüÜ][a-zA-ZäÄöÖüÜß -]+$/)) {
		isValidCity = false;
		errorMessageCity += 'Bitte geben Sie den Namen einer Stadt ein (oder aber eine PLZ).';
	}
		
	if(!isValidZipCode && !isValidCity && !fieldObjZipcode.className.match(/(?:\s|^)erroneous(?:\s|$)/)) {
		addErrorMessage(fieldObjZipcode, errorMessageZipcode);
	}
	if(!isValidZipCode && !isValidCity && !fieldObjCity.className.match(/(?:\s|^)erroneous(?:\s|$)/)) {
		addErrorMessage(fieldObjCity, errorMessageCity);
	}
	
	return isValidZipCode || isValidCity;
}


function addErrorMessage(fieldObj, errorMessage) {
	fieldObj.className = "erroneous";
	var spanObj = document.createElement("span");
	spanObj.className = "errorMessageInline";
	spanObj.appendChild(document.createTextNode(errorMessage));
	fieldObj.parentNode.insertBefore(spanObj, fieldObj.nextSibling);
	fieldObj.focus();
}


//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageDimensions(){
	
	var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	if (self.innerHeight) {	// all except Explorer
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	
	// for small pages with total height less then height of the viewport
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

	// for small pages with total width less then width of the viewport
	if(xScroll < windowWidth){	
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}


	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
	return arrayPageSize;
}