function form_validate()
{
	var ok;
	ok = true;
	var gewaehlt = false;

	var bYears = false,
		oYears = document.formAbo.nYears;

	if (oYears.length > 0)
	{
		for (var i=0;i != oYears.length;i++)
		{
			if (oYears[i].checked)
				bYears = true;
		}
	}

	var bStart = false,
		oStart = document.formAbo.szStart;

	if (oStart.length > 0)
	{
		for (var i=0;i != oStart.length;i++)
		{
			if (oStart[i].checked)
				bStart = true;
		}
	}

	if (!bYears && ok)
	{
		if (bStart)
		{
			alert('Please select number of years for subscription!')
	  		ok = false;
		}
	}

	if (!bStart && ok)
	{
		if (bYears)
		{
	  		alert('Please select the start issue of your subscription!')
	  		ok = false;
		}
	}

	var bIssues = false,
		oIssues = document.getElementsByName('aIssues[]');
	for (var i=0;i != oIssues.length;i++)
	{
		if (oIssues[i].checked)
			bIssues = true;
	}

	if (!bYears && !bStart && !bIssues && ok)
	{
		alert("No subscription options or back issues selected!");
		ok = false;
	}

	if (document.formAbo.szFirstName.value == "" && ok){
	  alert('First Name incorrect!');
	  ok = false;
	  document.formAbo.szFirstName.focus();
	}

	if (document.formAbo.szLastName.value == "" && ok){
	  alert('Last Name incorrect!');
	  ok = false;
	  document.formAbo.szLastName.focus();
	}

	if (document.formAbo.szAddress.value == "" && ok){
          alert('Address incorrect!')
	  ok = false;
	  document.formAbo.szAddress.focus();
	}

	if (document.formAbo.nPLZ.value == "" && ok){
          alert('Post Code / Zip Code incorrect!')
	  ok = false;
	  document.formAbo.nPLZ.focus();
	}

	if (document.formAbo.szLocation.value == "" && ok){
          alert('City / Town incorrect!')
	  ok = false;
	  document.formAbo.szLocation.focus();
	}

	if (document.formAbo.szCountry.value == "" && ok){
          alert('Country incorrect!')
	  ok = false;
	  document.formAbo.szCountry.focus();
	}

	if (document.formAbo.szMail.value == "" && ok){
	  		alert('E-Mail incorrect!')
	  		ok = false;
	  		document.formAbo.szMail.focus();
	}

	if (document.formAbo.szMail.value != "" && ok){
    	if(document.formAbo.szMail.value.indexOf('@') == -1){
	  		alert('E-Mail incorrect!')
	  		ok = false;
	  		document.formAbo.szMail.focus();
		}
	}

	var bPaymentID = false,
		oPaymentID = document.formAbo.szPaymentID;

	if (oPaymentID.length > 0)
	{
		for (var i=0;i != oPaymentID.length;i++)
		{
			if (oPaymentID[i].checked)
				bPaymentID = true;
		}
	}

	if (!bPaymentID && ok)
	{
	  		alert('No payment type selected!')
	  		ok = false;
	}

	return ok;
}