function validate_email(field)
{
	with (field)
	{
		apos=value.indexOf("@");
		dotpos=value.lastIndexOf(".");
		if (apos<1||dotpos-apos<2) 
		{
			return false;
		}
		else
		{
			return true;
		}
	}
}

function validate_name(field)
{
	with (field)
	{
		if(field.value!="")
		{
			return true;
		}
		else
		{
			return false;
		}
	}
}

function validate_zip(field)
{
	with (field)
	{
		if(field.value.length==4 && isNaN(field.value)==false)
		{
			return true;
		}
		else
		{
			return false;
		}
	}
}

function validate_sex(field)
{
	with (field)
	{
		if(field.value=="")
		{
			return false;
		}
		else
		{
			return true;
		}
	}
}

function validate_dob(field)
{
	with (field)
	{
		if(field.value=="")
		{
			return false;
		}
		else
		{
			return true;
		}
	}
}

function validate_form(thisform)
{
	with(thisform)
	{
		errFirstname = "";
		errLastname = "";
		errEmail = "";
		errZip = "";
		errSex = "";
		errDob = "";
		if(validate_email(email)==false){
			errEmail = "- E-mail\n";
		}
		if(validate_name(firstname)==false){
			errFirstname = "- Fornavn\n";
		}
		if(validate_name(lastname)==false){
			errLastname = "- Efternavn\n";
		}
		if(validate_zip(zip)==false){
			errZip = "- Postnummer\n";
		}
		if(validate_sex(sex)==false){
			errSex = "- Køn\n";
		}
		if(validate_dob(dob)==false){
			errDob = "- Fødselsår\n";
		}

		if(errEmail!="" || errFirstname!="" || errLastname!="" || errZip!="" || errSex!="" || errDob!="")
		{
			alert("Følgende felter blev ikke udfyld korrekt:\n\n"+ errFirstname + errLastname + errEmail + errZip + errSex + errDob);
			return false;
		}
		else
		{
			return true;
		}
	}
}