var cleanValidator = {
    init: function(settings) {
        this.settings = settings;
        this.form = document.getElementById(this.settings["formId"]);
        formInputs = this.form.getElementsByTagName("input");

        // change color of inputs on focus
        for (i = 0; i < formInputs.length; i++) {
            if (formInputs[i].getAttribute("type") != "submit") {
                input = formInputs[i];
                //input.style.background = settings["inputColors"][0];
                input.onblur = function() {
                    //this.style.background = settings["inputColors"][0];
                }
                input.onfocus = function() {
                    //this.style.background = settings["inputColors"][1];
                }
            }
        };
        this.form.onsubmit = function() {
            error = cleanValidator.validate();
            if (error.length < 1) {
                return true;
            } else {
                cleanValidator.printError(error);
                return false;
            }
        };
    },
    validate: function() {
        error = '';
        validationTypes = new Array("isRequired", "isEmail", "isNumeric");
        for (n = 0; n < validationTypes.length; n++) {
            var x = this.settings[validationTypes[n]];
            if (x != null) {
                for (i = 0; i < x.length; i++) {
                    inputField = document.getElementById(x[i]);
                    switch (validationTypes[n]) {
                        case "isRequired":
                            valid = !isRequired(inputField.value);
                            errorMsg = "is a required field.";
                            break;
                        case "isEmail":
                            valid = isEmail(inputField.value);
                            errorMsg = "is an invalid email address.";
                            break;
                        case "isNumeric":
                            valid = isNumeric(inputField.value);
                            errorMsg = "can only be a number.";
                            break;
                    }
                    if (!valid) {
                        error += x[i] + " " + errorMsg + "\n";
                        //inputField.style.background = this.settings["errorColors"][0];
                        //inputField.style.border = "1px solid "+this.settings["errorColors"][1];
                    } else {
                        //inputField.style.background = this.settings["inputColors"][0];
                        //inputField.style.border = '1px solid';
                    }
                }
            }
        }
        return error;
    },
    printError: function(error) {
        alert(error);
    }
};

// returns true if the string is not empty
function isRequired(str){
	return (str == null) || (str.length == 0);
}
// returns true if the string is a valid email
function isEmail(str){
	if(isRequired(str)) return false;
	var re = /^[^\s()<>@,;:\/]+@\w[\w\.-]+\.[a-z]{2,}$/i
	return re.test(str);
}
// returns true if the string only contains characters 0-9 and is not null
function isNumeric(str){
	if(isRequired(str)) return false;
	var re = /[\D]/g
	if (re.test(str)) return false;
	return true;
}