function validate(parameters){  
    if(parameters.username === undefined){
        return "Username is missing";
    }
    if(typeof parameters.username !== "string"){
        return "Username must be a string";
    }
    if(typeof parameters.username.length < 3){
        return "Username must be at least 3 characters long";
    }

    if(parameters.id === undefined){
        return "Id is missing";
    }
    if(typeof parameters.id !== "number" || parameters.id % 1 !== 0){
        return "Id must be an integer";
    }
    if(parameters.id < 1){
        return "Id must be greater than 1";
    }
}