function QMFormValidator(formName) {
	
	this.form = document.forms[formName];
	this.add = QMFormValidator_add;
	this.validate = QMFormValidator_validate;
	this.setCustomValidation = QMFormValidator_custom;
	this.customValidation = null;
	this.form.qmValidator = this;

	function QMFormValidator_add(inputName, validatorName, params) {
		var input = this.form[inputName];
		if (!input.qmValidators) {
			input.qmValidators = new Array();
		}
		var i = input.qmValidators.length;
		switch (validatorName) {
			case 'int':
			case 'integer':
				input.qmValidators[i] = new QMIntegerValidator(input, params);
				break;
			case 'float':
			case 'double':
			case 'decimal':
				input.qmValidators[i] = new QMDecimalValidator(input, params);
				break;
			case 'date':
				input.qmValidators[i] = new QMDateValidator(input, params);
				break;
			case 'regexpr':
				input.qmValidators[i] = new QMRegexprValidator(input, params);
				break;
			case 'email':
				input.qmValidators[i] = new QMEmailValidator(input, params);
				break;
			case 'req':
			case 'required':
				input.qmValidators[i] = new QMRequiredValidator(input, params);
				break;
			case 'length':
				input.qmValidators[i] = new QMLengthValidator(input, params);
				break;
			case 'range':
				input.qmValidators[i] = new QMRangeValidator(input, params);
				break;
			case 'dontselect':
				input.qmValidators[i] = new QMSelectValidator(input, params);
				break;
		}
		
	}
	
	function QMFormValidator_validate() {
		var n = this.form.elements.length;
		var m = 0;
		var valid = true;
		for (i=0; i<n; i++) {
			if (this.form.elements[i].qmValidators) {
				m = this.form.elements[i].qmValidators.length;
				for (j=0; j<m; j++) {
					valid = this.form.elements[i].qmValidators[j].validate();
					if (!valid) {
						try {
							this.form.elements[i].focus();
						} catch (e) {}
						return false;
					}
				}
			}
		}
		if (this.customValidation) {
			return this.customValidation();
		}
		return true;
	}
	
	function QMFormValidator_custom(fn) {
		this.customValidation = fn;
	}
}

function QMIntegerValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMIntegerValidator_validate;
	function QMIntegerValidator_validate() {
		var value = parseInt(this.input.value);
		if (this.input.value.length > 0 && isNaN(value)) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("Invalid number format.");
			}
			return false;
		}
		return true;
	}
}

function QMDecimalValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMDecimalValidator_validate;
	function QMDecimalValidator_validate() {
		var value = parseFloat(this.input.value);
		if (this.input.value.length > 0 && isNaN(value)) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("Invalid number format.");
			}
			return false;
		}
		return true;
	}
}

function QMDateValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMDateValidator_validate;
	function QMDateValidator_validate() {
		var pattern = /^((?:19|20)\d\d)\-((?:0?[1-9])|(?:1[0-2]))\-((?:0?[1-9])|(?:[12]\d)|(?:3[01]))$/;;
		if (this.params.pattern) { 
			pattern = this.params.pattern 
		}
		if (this.input.value.length > 0 && !pattern.test(this.input.value)) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("Invalid date format.");
			}
			return false;
		}
		return true;
	}
}

function QMFullDateValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMDateValidator_validate;
	function QMDateValidator_validate() {
		var pattern = /^\d{4}\-\d{2}\-\d{2}\s(0[1-9]|1\d|2[0-3]):([0-5]\d):([0-5]\d)$/;
		if (this.params.pattern) { 
			pattern = this.params.pattern 
		}
		if (this.input.value.length > 0 && !pattern.test(this.input.value)) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("Invalid date format.");
			}
			return false;
		}
		return true;
	}
}


function QMRegexprValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMRegexprValidator_validate;
	function QMRegexprValidator_validate() {
		var pattern = params.regexpr;
		if (this.input.value.length > 0 && !pattern.test(this.input.value)) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("Invalid format.");
			}
			return false;
		}
		return true;
	}
}

function QMEmailValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMEmailValidator_validate;
	function QMEmailValidator_validate() {
		var pattern = /^[a-zA-Z0-9\-_.]+@[a-zA-Z0-9\-_]+(\.[a-zA-Z0-9\-_]+)+$/;
		if (this.input.value.length > 0 && !pattern.test(this.input.value)) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("Invalid email format.");
			}
			return false;
		}
		return true;
	}
}

function QMRequiredValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMRequiredValidator_validate;
	function QMRequiredValidator_validate() {
		var value = this.input.value.replace(/^\s*|\s*$/g, "");
		if (value.length == 0) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("Required field.");
			}
			return false;
		}
		return true;
	}
}

function QMLengthValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMLengthValidator_validate;
	function QMLengthValidator_validate() {
		var value = this.input.value.replace(/^\s*|\s*$/g, "");
		var minL = (this.params.min ? this.params.min : 0);
		var maxL = (this.params.max ? this.params.max : 999999);
		if (value.length < minL || value.length > maxL) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("The field must have between " + minL + " and " + maxL + " characters.");
			}
			return false;
		}
		return true;
	}
}

function QMRangeValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMRangeValidator_validate;
	function QMRangeValidator_validate() {
		var value = parseFloat(this.input.value);
		var valid = true;
		var rMin = "-inf";
		var rMax = "inf";
		if (this.params.min && value < this.params.min) {
			valid = false;
			rMin = this.params.min;
		}
		if (this.params.max && value > this.params.max) {
			valid = false;
			rMax = this.params.max;
		}
		if (!valid) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("The field is out of range [" + rMin + ", " + rMax + "].");
			}
			return false;
		}
		return true;
	}
}

function QMSelectValidator(input, params) {
	this.input = input;
	this.params = params;
	this.validate = QMSelectValidator_validate;
	function QMSelectValidator_validate() {
		if (this.input.selectedIndex == this.params.dontSelect) {
			if (this.params.message) {
				alert(this.params.message);
			}
			else {
				alert("The field is required.");
			}
			return false;
		}
		return true;
	}
}