// Removes the last element from an array and returns that element.
if (!Array.prototype.pop) {
	Array.prototype.pop = function() {
		var last;
		if (this.length) {
			last = this[this.length - 1];
			this.length -= 1;
		}
		return last;
	};
}

// Adds one or more elements to the end of an array and returns the new length of the array.
if (!Array.prototype.push) {
	Array.prototype.push = function() {
		for (var i = 0; i < arguments.length; ++i) {
			this[this.length] = arguments[i];
		}
		return this.length;
	};
}

// Removes the first element from an array and returns that element.
if (!Array.prototype.shift) {
	Array.prototype.shift = function() {
		var first;
		if (this.length) {
			first = this[0];
			for (var i = 0; i < this.length - 1; ++i) {
				this[i] = this[i + 1];
			}
			this.length -= 1;
		}
		return first;
	};
}

// Adds one or more elements to the front of an array and returns the new length of the array.
if (!Array.prototype.unshift) {
	Array.prototype.unshift = function() {
		if (arguments.length) {
			var i, len = arguments.length;
			for (i = this.length + len - 1; i >= len; --i) {
				this[i] = this[i - len];
			}
			for (i = 0; i < len; ++i) {
				this[i] = arguments[i];
			}
		}
		return this.length;
	};
}

// Adds and/or removes elements from an array.
if (!Array.prototype.splice) {
	Array.prototype.splice = function(index, howMany) {
		var elements = [], removed = [], i;
		for (i = 2; i < arguments.length; ++i) {
			elements.push(arguments[i]);
		}
		for (i = index; (i < index + howMany) && (i < this.length); ++i) {
			removed.push(this[i]);
		}
		for (i = index + howMany; i < this.length; ++i) {
			this[i - howMany] = this[i];
		}
		this.length -= removed.length;
		for (i = this.length + elements.length - 1; i >= index + elements.length; --i) {
			this[i] = this[i - elements.length];
		}
		for (i = 0; i < elements.length; ++i) {
			this[index + i] = elements[i];
		}
		return removed;
	};
}