function doesNotExist(variable) {
    if (variable === undefined || variable === null) {
        return true;
    }
    return false;
}

function exists(variable) {
    if (variable === undefined || variable === null) {
        return false;
    }
    return true;
}

function isTypeof(type, variable) {
    try {
        if (doesNotExist(type)) {
            throw "type is undefined";
        }
        if (doesNotExist(variable)) {
            throw "variable is undefined";
        }
        if (variable.constructor == type) {
            return true;
        }
        else {
            return false;
        }
    }
    catch (error) {
        document.writeln(error);
    }
}

function isNumber(number) {
    var pattern = /^-?\d+(?:\.\d*)?(?:e[+\-]?\d+)?$/i;
    return pattern.test(number);
}

if (doesNotExist(Function.prototype['method'])) {
    Function.prototype.method = function (name, func) {
        try {
            if (doesNotExist(name)) {
                throw "You must give a name to the method";
            }
            if (doesNotExist(func)) {
                throw "You must define a function for the method";
            }

            if (doesNotExist(this.prototype[name])) {
                this.prototype[name] = func;
                return this;
            }
        }
        catch (error) {
            alert(error);
        }
    };
}

String.method('is_empty', function () {
    if (this == '' && this.length === 0) {
        return true;
    }
    return false;
});

String.method('trim', function () {
    return this.replace(/^\s+|\s+$/g, "");
});

String.method('ltrim', function () {
    return this.replace(/^\s+/, "");
});

String.method('rtrim', function () {
    return this.replace(/\s+$/, "");
});

String.method('each', function (callback) {
    for (var i = 0; i < this.length; i++) {
        callback.call(this, this[i]);
    }
});

String.method('capitalize', function () {
    return this.substr(0, 1).toUpperCase() + this.substr(1);
});

String.method('reverse', function () {
    var reversed_string = '';
    for (var i = this.length - 1; i >= 0; i--) {
        reversed_string += this.charAt(i);
    }
    return reversed_string;
});

String.method('to_n', function () {
    return parseInt(this, 10);
});

Array.method('is_empty', function () {
    return (this.length < 1) ? true : false;
});

Array.method('each', function (callback) {
    for (i = 0; i < this.length; i++) {
        callback.call(this, this[i]);
    }
});

Array.method('contains', function (value) {
    for (i = 0; i < this.length; i++) {
        if (this[i] === value) {
            return true;
        }
    }
    return false;
});

function getUrlParameter(param) {
    param = param.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");

    var regexS = "[\\?&]" + param + "=([^&#]*)";
    var regex = new RegExp(regexS);
    var results = regex.exec(window.location.href);
    if (results == null)
        return "";
    else
        return unescape(results[1]);
}

// null console for browsers without one
if (window['console'] === undefined) {
    window.console = {
        log: function (message) {
            // Do nothing
        },
        time: function (message) {
            // Do nothing
        },
        timeEnd: function (message) {
            // Do nothing
        }
    };
}

if (window.jQuery) {
    jQuery.fn.log = function (msg) {
        console.log("%s: %o", (msg || 'Log'), this);
        return this;
    };
}