Returns a new object with only the keys provided as arguments, leaves old object intact

object.slice.js

if(!Object.prototype.slice){
	Object.prototype.slice = function(){
		var returnObj = {};
		for(var i = 0, j = arguments.length; i < j; i++){
			if(this.hasOwnProperty(arguments[i])){
				returnObj[arguments[i]] = this[arguments[i]];
			}
		}
		return returnObj;
	}
}