function is_non_empty(field){
	var re = /\s/g; //Match any white space including space, tab, form-feed, etc. 
	var field = field.replace(re, '');
	if(field.length == 0){
		//alert('Field empty or has only spaces!');
		return -1;
	}else{
		//alert('Field ok!');
		return 1;
	}
}

function is_valid_email(field){
	var emailFilter=/^([a-zA-Z0-9_\+%.-])+([a-zA-Z0-9\._\+-])*@([a-zA-Z0-9-])+\.([a-zA-Z0-9]){2,4}$/;
	if(field.search(emailFilter) == (-1)){
		//alert('Field is not valid email!');
		return -1;
	}else{
		//alert('Field ok!');
		return 1;
	}
}

function is_valid_website(field){

	//var check = /^(ftp|https?)\:\/\/+[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?$/;
	var check = /^[a-zA-Z0-9\/\-\.:]+\.[a-zA-Z]{2,4}(\/\S*)?$/;

//	var check = /^(.)+\.([a-zA-Z]){2,4}\/{0,1}$/;
	if (!check.test(field)) {
		return -1;
	} else {
		return 1;
	}
}

function validate(form){
	var message = '';
	var name = form.name.value;
	var email = form.email.value;
	var email2 = form.email2.value;
	var site_url = form.site_url.value;
	if(is_non_empty(name) == (-1)){
		message += "Please enter a valid name!";
	}
	if(is_non_empty(email) == (-1) || is_valid_email(email) == (-1)){
		if(message!=''){
			message += "\n";
		}
		message += "Please enter a valid email!";
	} else if (email != email2) {
		if(message!=''){
			message += "\n";
		}
		message += "Email and confirmation email do not match!";
	}
	
	if(is_non_empty(site_url) == (-1) || is_valid_website(site_url) == (-1)){
		if(message!=''){
			message += "\n";
		}
		message += "Please enter a valid url.";
	}
		
	if(message){
		alert(message);
		return false;
	}else{
		
		return true;
	}
}