Javascript required version check

is_required_version.js

/*

Test if the current version meets the required version number.

Examples:
 
Basic Usage

	if (is_required_version("1.2.6", "1.1.3") === false) {
		alert("This script requires version 1.2.6 and the current script's version is 1.1.3");
	}
 
Test if the currently loaded version of jQuery meets a jQuery plugin requirements.

	if (typeof jQuery !== "function") {
		throw new Error("jQuery isn't loaded, please load jQuery 1.2.6 or greater in order to use this plugin.");
	}
	
	if (is_required_version("1.2.6", $.fn.jquery) === false) {
		throw new Error("This plugin requires jQuery 1.2.6. and the current version of jQuery is "+ $.fn.jquery +".");
	}

*/
function is_required_version(required, current) {
	var cv_arr = current.split(".");
	var rv_arr = required.split(".");
	for (i=0; i <= cv_arr.length-1; i++) {
		cv_num = (typeof cv_arr[i] !== 'undefined' && isNaN(cv_arr[i]) === false) ? parseInt(cv_arr[i], 10) : NaN;
		rv_num = (typeof rv_arr[i] !== 'undefined' && isNaN(rv_arr[i]) === false) ? parseInt(rv_arr[i], 10) : NaN;

		if (cv_num > rv_num) {
			return true;
		} else if ((cv_num === rv_num) && typeof rv_arr[i+1] === "undefined") {
			return true;
		}
	}
	return false;
}