function strpos (haystack, needle, offset) {
    // Finds position of first occurrence of a string within another  
    // 
    // version: 1102.614
    // discuss at: http://phpjs.org/functions/strpos
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Onno Marsman    
    // +   bugfixed by: Daniel Esteban
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // *     example 1: strpos('Kevin van Zonneveld', 'e', 5);
    // *     returns 1: 14
    var i = (haystack + '').indexOf(needle, (offset || 0));
    return i === -1 ? false : i;
}
function oscuraElementiClasse(findClass) {
var aElm=document.body.getElementsByTagName('*');

for(var i=0; i<aElm.length; i++) {
	 if((strpos(aElm[i].className,findClass))>0) {
		aElm[i].style.display="none";    		
        }
    }        
}