function trim(str) {
	var newstr = str.replace(/^\s*(.+?)\s*$/, "$1");
	if (newstr == " ") return "";
	return newstr;
}

function drop_spaces(str) {
	var newstr = trim(str);
	return newstr.replace(/(\s)+/g, ""); 
}

function check_email(email)
{
	var template = /^[A-Za-z0-9](([_\.\-]?[a-zA-Z0-9]+)*)@([A-Za-z0-9]+)(([\.\-]?[a-zA-Z0-9]+)*)\.([A-Za-z])+$/;
	email = drop_spaces(email);
	if (template.test(email)) return true;
	return false; 
}

function check_submit()
{
	if(document.getElementById('submit_name').value.length == 0)
	{
		alert("Please enter your name");
		return false;
	}
	
	if(document.getElementById('submit_mail').value.length == 0 || !check_email(document.getElementById('submit_mail').value))
	{
		alert("Please enter valid e-mail");
		return false;
	}

	if(document.getElementById('submit_rate').value == 0)
	{
		alert("Please choose rating");
		return false;
	}
	
	if(document.getElementById('submit_text').value.length == 0)
	{
		alert("Please enter your review");
		return false;
	}

	return true;
}