function fieldFocus(id,wert,defaultwert) {
	if(wert == defaultwert) {
		document.getElementById(id).value = "";
		}
	}
function fieldBlur(id,wert,defaultwert) {
	if(wert.replace(/ /g,"") == "" || wert == defaultwert) {
		document.getElementById(id).value = defaultwert;
		}
	}
function openDivCentered (contentDiv,overlayDiv,contentDivWidth,contentDivHeight) {
	// First, determine how much the visitor has scrolled
	var scrolledX, scrolledY;
	if (self.pageYOffset) {
		scrolledX = self.pageXOffset;
		scrolledY = self.pageYOffset;
		}
	else if (document.documentElement && document.documentElement.scrollTop) {
		scrolledX = document.documentElement.scrollLeft;
		scrolledY = document.documentElement.scrollTop;
		}
	else if (document.body) {
		scrolledX = document.body.scrollLeft;
		scrolledY = document.body.scrollTop;
		}
	// Next, determine the coordinates of the center of browser's window
	var centerX, centerY;
	if (self.innerHeight) {
		centerX = self.innerWidth;
		centerY = self.innerHeight;
		}
	else if (document.documentElement && document.documentElement.clientHeight) {
		centerX = document.documentElement.clientWidth;
		centerY = document.documentElement.clientHeight;
		}
	else if (document.body) {
		centerX = document.body.clientWidth;
		centerY = document.body.clientHeight;
		}
	// contentDivWidth is the width of the div, contentDivHeight is the height of the
	// div passed as arguments to the function:
	var leftOffset = scrolledX + (centerX - contentDivWidth) / 2;
	var topOffset = scrolledY + (centerY - contentDivHeight) / 2;
	// The initial width and height of the div can be set in the
	// style sheet with display:none; contentDiv is passed as an argument to the function
	var divStyle = document.getElementById(contentDiv).style;
	divStyle.top = topOffset + "px";
	divStyle.left = leftOffset + "px";
	divStyle.width = contentDivWidth + "px";
	divStyle.height = contentDivHeight + "px";
	divStyle.display = "block";
	document.getElementById(overlayDiv).style.display = "block";
	}
function closeDivCentered (contentDiv,overlayDiv) {
	document.getElementById(contentDiv).style.display = "none";
	document.getElementById(overlayDiv).style.display = "none";
	}