Array.prototype.sum = function(){
	for(var i=0,sum=0;i<this.length;sum+=this[i++]);
	return sum;
}
Array.prototype.max = function(){
	return Math.max.apply({},this)
}
Array.prototype.min = function(){
	return Math.min.apply({},this)
}
Array.prototype.indexOf = function(elt /*, from*/){
    var len = this.length;
    var from = Number(arguments[1])||0;
    
    from = (from < 0)? Math.ceil(from):Math.floor(from);    
    if (from < 0){
      from += len;
    }    
    for (; from < len; from++){
        if (from in this&&this[from]===elt)
        return from;
    }    
    return -1;
}
Array.prototype.find = function(searchStr) {
  var returnArray = false;
  for (i=0; i<this.length; i++) {
    if (typeof(searchStr) == 'function') {
      if (searchStr.test(this[i])) {
        if (!returnArray) { returnArray = [] }
        returnArray.push(i);
      }
    } else {
      if (this[i]===searchStr) {
        if (!returnArray) { returnArray = [] }
        returnArray.push(i);
      }
    }
  }
  return returnArray;
}