function doBlink(cls) {
   blinks = getElementsByClassName(document, "*", cls);
   for(i = 0; i<blinks.length; i++) {
      blinks[i].style.visibility = blinks[i].style.visibility == "" ? "hidden" : "";
   }
}

/*
    Written by Jonathan Snook, http://www.snook.ca/jonathan
    Add-ons by Robert Nyman, http://www.robertnyman.com
*/
function getElementsByClassName(oElm, strTagName, strClassName){
    var arrElements = (strTagName == "*" && oElm.all)? oElm.all : oElm.getElementsByTagName(strTagName);
    var arrReturnElements = new Array();
    strClassName = strClassName.replace(/\-/g, "\\-");
    var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$)");
    var oElement;
    for(var i=0; i<arrElements.length; i++){
        oElement = arrElements[i];      
        if(oRegExp.test(oElement.className)){
            arrReturnElements.push(oElement);
        }   
    }
    return (arrReturnElements)
}