/**
 * Functions for checking entered values of a form
 * 
 * @package download
 * @author Igor Volynets
 * @copyright Copyright (c) 2008, Digital House Ltd.
 */

/**
 * Visible style variables
 */

NORMAL_STYLE = "input";
HIGHLIGHT_STYLE = "hl_input";

/**
 * Trims left spaces of a string
 */

function ltrim(text) {
	var ptrn = /\s*((\S+\s*)*)/;
	return text.replace(ptrn, "$1");
}

/**
 * Trims right spaces of a string
 */

function rtrim(text) {
	var ptrn = /((\s*\S+)*)\s*/;
	return text.replace(ptrn, "$1");
}

/**
 * Trims spaces from both sides of a string
 */

function trim(text) {
	return ltrim(rtrim(text));
}

/**
 * Checks entered form values
 */

function check_values(form) {
	
	var valid = true;
	
	for (var i = 0; i < form.elements.length; i++) {
		if (form.elements[i].type == "text" || form.elements[i].type == "password") {
			if (trim(form.elements[i].value) == "") {
				form.elements[i].className = HIGHLIGHT_STYLE;
				valid = false;
			}
			else {
				form.elements[i].className = NORMAL_STYLE;				
			}
		}
	}
	
	if (!valid) {
		alert("Please fill out the entire form");
		return false;
	}
	
	var em = document.getElementById("email");
	
	if (!em.value.match(/^[a-zA-Z0-9\._\-]+@([a-zA-Z0-9\._\-]+(\.[a-zA-Z0-9]+)+)*$/)) {
		em.className = HIGHLIGHT_STYLE;
		alert("Entered e-mail address has invalid format");
		return false;
	}
	else {
		em.className = NORMAL_STYLE;
	}
	
}

/**
 * Clears form
 */

function clear_form(form_id) {
	var form = document.getElementById(form_id);
	for (var i = 0; i < form.elements.length; i++) {
		if (form.elements[i].type == "text" || form.elements[i].type == "password") {
			form.elements[i].value = "";
			form.elements[i].className = NORMAL_STYLE;
		}
	}
	return false;
}