String.prototype.trim = function() {
    return this.replace(/^\s+|\s+$/g, "");
}
String.prototype.ltrim = function() {
    return this.replace(/^\s+/, "");
}
String.prototype.rtrim = function() {
    return this.replace(/\s+$/, "");
}

String.prototype.removeSpaces = function() {
    return this.replace(/\s+/, "");
}

String.prototype.validateMail=function() {
    var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
    return emailPattern.test(this);
}