/*
	getElementsByClassName is developed by Robert Nyman, http://www.robertnyman.com
	Code/licensing: http://code.google.com/p/getelementsbyclassname/
*/
    var getElementsByClassName = function (className, tag, elm){
	if (document.getElementsByClassName) {
		getElementsByClassName = function (className, tag, elm) {
			elm = elm || document;
			var elements = elm.getElementsByClassName(className),
				nodeName = (tag)? new RegExp('\\b' + tag + '\\b', 'i') : null,
				returnElements = [],
				current;
			for(var i=0 ; i<elements.length; i++){
				current = elements[i];
				if(!nodeName || nodeName.test(current.nodeName)) {
					returnElements[returnElements.length]=current;
				}
			}
			return returnElements;
		};
	}
	else if (document.evaluate) {
		getElementsByClassName = function (className, tag, elm) {
			tag = tag || '*';
			elm = elm || document;
			var classes = className.split(' '),
				classesToCheck = '',
				xhtmlNamespace = 'http://www.w3.org/1999/xhtml',
				namespaceResolver = (document.documentElement.namespaceURI === xhtmlNamespace)? xhtmlNamespace : null,
				returnElements = [],
				elements,
				node;
			for(var j=0; j<classes.length; j++){
				classesToCheck += '[contains(concat(" ", @class, " "), " ' + classes[j] + ' ")]';
			}
			try	{
				elements = document.evaluate('.//' + tag + classesToCheck, elm, namespaceResolver, 0, null);
			}
			catch (e) {
				elements = document.evaluate('.//' + tag + classesToCheck, elm, null, 0, null);
			}
			while ((node = elements.iterateNext())) {
				returnElements[returnElements.length]=node;
			}
			return returnElements;
		};
	}
	else {
		getElementsByClassName = function (className, tag, elm) {
			tag = tag || '*';
			elm = elm || document;
			var classes = className.split(' '),
				classesToCheck = [],
				elements = (tag === '*' && elm.all)? elm.all : elm.getElementsByTagName(tag),
				current,
				returnElements = [],
				match;
			for(var k=0 ; k<classes.length ; k++){
				classesToCheck[classesToCheck.length]=new RegExp('(^|?:\\s)' + classes[k] + '(?:\\s|$)');
			}
			for(var l=0 ; l<elements.length ; l++){
				current = elements[l];
				match = false;
				for(var m=0 ; m<classesToCheck.length ; m++){
					match = classesToCheck[m].test(current.className);
					if (!match) {
						break;
					}
				}
				if (match) {
					returnElements[returnElements.length]=current;
				}
			}
			return returnElements;
		};
	}
	return getElementsByClassName(className, tag, elm);
};


function gest_spam() {

    var b = getElementsByClassName('spam');

    for (var i=0 ; i<b.length ; i++)  {
       b[i].innerHTML = '';
    }
}