Common={}
/***********************************************************************
 getElementsByClassName(classname, tagName, parent)
 
Retrieves all elements in parent document matching the given classname.
Tag name and parent are not mandatory.
***********************************************************************/
Common.getElementsByClassName=function (classname,tagName,parent) {
	var result=new Array ()
	if (tagName == null) tagName="*"
	if (parent == null) parent=document
	var elements=parent.getElementsByTagName(tagName)
	var elLen=elements.length
	for (var i=0, j=0; i<elLen; i++) {
		if (null == classname || elements[i].className == classname) {
			result[j]=elements[i]
			j++
		}
	}
	return result
}

/***********************************************************************
get_hex_color (r, g, b)

This function returns a color string given red, green, and blue integers
between 0 and 255.
***********************************************************************/
Common.getHexColor=function (r,g,b) {
	var hexString="0123456789abcdef"
	var hexColor=
		hexString.charAt (Math.floor (r / 16))
	+	hexString.charAt (r % 16)
	+	hexString.charAt (Math.floor (g / 16))
	+	hexString.charAt (g % 16)
	+	hexString.charAt (Math.floor (b / 16))
	+	hexString.charAt (b % 16)
	return hexColor
}

/***********************************************************************
isIE ()

Returns true if the browser is one of Microsoft's Internet Explorers.
***********************************************************************/
Common.isIE=function () {
	var agt=navigator.userAgent.toLowerCase ()
	return ((agt.indexOf ("msie") != -1) && (agt.indexOf ("opera") == -1))
}

/***********************************************************************
isIE ()

Returns true if the browser is one of Microsoft's Internet Explorers.
***********************************************************************/
Common.getElementOpacity=function (eElement) {
	if (!Common.isIE ())
		if (eElement.style.opacity)
			return parseFloat (eElement.style.opacity);
		else return null
	else {
		var base=eElement.style.filter
		if (base.substr (0,13) == "alpha(opacity") {
			var amount=base.substr (14,base.length - 15)
			return parseInt (amount) / 100
		}
		else return null
	}
}

Common.setElementOpacity=function (eElement,fOpacity) {
	if (!Common.isIE ()) eElement.style.opacity=fOpacity
	else eElement.style.filter="alpha(opacity=" + (fOpacity * 100) + ")"
}