function validate_form()
{
	var error = "";
	var contact_form = document.getElementById('contact_form');
	if(contact_form.name.value == "")
	{
		error = "You need to fill in your name.\n";
	}
	if(contact_form.phone.value == "" && error == "")
	{
		if(contact_form.email.value == "" && error == "")
		{
			error = "You need to fill in either your phone or email.\n";
		}
		else
		{
			if(echeck(contact_form.email.value) == false && error == "")
			{
				error = "Please enter a proper email address\n";
			}
		}
	}
	if(contact_form.enquiry.value == "" && error == "")
	{
		error = "You need to provide an enquiry.\n";
	}
	if(error == "")
	{
		contact_form.submit.disabled = true;
		contact_form.submit.value = "Sending";
		return true;
	}
	else
	{
		alert(error);
		return false;
	}
}

function echeck(str) 
{
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1)
	{
		return false
	}
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
	{
		return false
	}
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr)
	{
		return false
	}
	if (str.indexOf(at,(lat+1))!=-1)
	{
		return false
	}
	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
	{
		return false
	}
	if (str.indexOf(dot,(lat+2))==-1)
	{
		return false
	}
	if (str.indexOf(" ")!=-1)
	{
		return false
	}
	return true					
}