function isblank(s)
{
	for(var i = 0; i < s.length; i++)
	{
		var c = s.charAt(i);
		if((c != ' ') && (c != '\n') && (c != '\t'))
			return false;
	}
	//window.alert("true");
	return true;
}

function validate_email(email){
if ((email.indexOf("@")==-1) || (email.indexOf(".")==-1) || (email.length<6)) 
	return false;
else
	return true;
}

function validateForm(form)
{
	var firstName = form.first_name;
	var lastName = form.last_name;
	var address=form.address;
	var city=form.city;
	var country = form.country;
	var usrChoice = country.selectedIndex;
	var zip_code=form.zip_code;
	var company= form.company;
	var phone = form.phone;
	var email = form.email;

	
	if(isblank(firstName.value) || (firstName.value == null))
	{
		window.alert("Please enter valid first name.");
		form.first_name.focus();
		return false;
	}
	
	if(isblank(lastName.value) || (lastName.value == null))
	{
		window.alert("Please enter valid last name.");
		form.last_name.focus();
		return false;
	}
	
	if(isblank(address.value) || (address.value == null))
	{
		window.alert("Please enter valid address.");
		form.address.focus();
		return false;
	}
	
	if(isblank(city.value) || (city.value == null))
	{
		window.alert("Please enter city.");
		form.city.focus();
		return false;
	}
	if((country.options[usrChoice].value == "0") ||(country.options[usrChoice].value == "1" ))
	{
		window.alert("Please select a country.");
		country.focus();
		return false;
	}

	if(isblank(zip_code.value) || (zip_code.value == null))
	{
		window.alert("Please enter zip code.");
		form.zip_code.focus();
		return false;
	}

	if(isblank(company.value) || (company.value == null))
	{
		window.alert("Please enter company name.");
		form.company.focus();
		return false;
	}

	if(isblank(phone.value) || (phone.value == null))
	{
		window.alert("Please enter phone number.");
		form.phone.focus();
		return false;
	}
	
	if(isblank(email.value) || !(validate_email(email.value)))
	{
		window.alert("Please enter valid email address.");
		email.focus();
		return false;
	}
	return true;
}