function validateField(item, reg) {
	if (reg.test(item.value)) {
		item.style.backgroundColor = "lightgreen";
		return true;
	} else {
		item.style.backgroundColor = "#FFF";
		return false;
	}	
}

function validEmail(item) {
	return validateField(item, /.@./);		
}

function validPhone(item) {
	return validateField(item, /^\d{3}\s{1}\d{3}\s{1}\d{3}$/);		
}

function validString(item, reg) {
	return validateField(item, reg);
}

function validForm1(base) {
	if (base.name.value.length < 3) {alert("Chybí jméno!"); return false;} 	
	
	if (!validPhone(base.phone)) {alert("Zadané telefonní číslo neodpovídá potřebnému formátu!"); return false;} 
	if (!validEmail(base.email)) {alert("Zadaná emailová adresa neodpovídá potřebnému formátu!"); return false;} 

	return true;
}

function validPass(item1, item2) {
	if (item1.value == item2.value) 
		return true;
	else {		
		alert("Zadaná hesla se neshodují!");
		return false;	
	}
	
}

function refreshForm1(base) {
	validString(base.name,/.{1}/);
	validString(base.surname,/.{1}/);
	
	validPhone(base.phone);
	validEmail(base.email);
	
	validString(base.password1,/.{5}/);
	validString(base.password2,/.{5}/);	
}


function refreshForm2(base) {
	validEmail(base.email);	
	validString(base.passwd,/.{5}/);
}


function generateExternalLink(url, text) {
	document.write("<a target=\"_blank\" href=\""+url+"\" class=\"ext-link\">"+text+"</a>");	
}

function generateEmailLink(mail1, mail2) {
	completeMail = (mail1 + "@" + mail2);
	document.write("<a class=\"email-link\" href=\"mailto:"+completeMail+"\">"+completeMail+"</a>");	
}

function generateEmail(mail1, mail2) {
	completeMail = (mail1 + "@" + mail2);
	document.location("mailto:"+completeMail);	
}

function checkLength(obj, i, counter) {		
	if (obj.value.length > i) { 
		obj.value = obj.value.substring(0, i);
		obj.style.backgroundColor = "red";			
		return;
	} else {
		obj.style.backgroundColor = "#ABAB77";
	}		
	counter.innerHTML = "Zbývá " + (i-obj.value.length) + " znaků";	
}


function validPostForm(obj) {
	validString(obj.author_name, /.{2}/);
	validEmail(obj.author_email) ;

}

function refreshPostForm(obj) {
	validEmail(obj.author_email);
	validString(obj.c_value, /.{2}/);
	validString(obj.author_name, /.{2}/);
	
}