function fnSend(){
  if(!document.frmMain.txtName.value){
		alert('Vul uw naam in a.u.b.');
		document.frmMain.txtName.focus();
	}
	else if(!document.frmMain.txtAddress.value){
		alert('Vul uw adres in a.u.b.');
		document.frmMain.txtAddress.focus();
    }
    else if(!document.frmMain.txtZipcode.value){
		alert('Vul uw postcode in a.u.b.');
		document.frmMain.txtZipcode.focus();
    }
    else if(!document.frmMain.txtCity.value){
		alert('Vul uw woonplaats in a.u.b.');
		document.frmMain.txtCity.focus();
    }
    else if(!document.frmMain.txtPhone.value){
		alert('Vul uw telefoonnummer in a.u.b.');
		document.frmMain.txtPhone.focus();
    }
    else if(!document.frmMain.txtEmail.value){
		alert('Vul uw e-mailadres in a.u.b.');
		document.frmMain.txtEmail.focus();
    }
	else if(!validateEmail(document.frmMain.txtEmail.value)){
		alert('Uw e-mailadres is niet juist.');
		document.frmMain.txtEmail.focus();
	}	
	else{
		document.frmMain.cmdSend.disabled = true;
		document.frmMain.submit();
	}
}

function validateEmail(str) {
	var index = str.indexOf("@");
	if ((index < 1) || (str.indexOf(".") < 1) || (str.indexOf("\"") > -1) || (str.indexOf("'") > -1) || (str.length < 5) || ((index > 2) && (str.indexOf("@", index+1) != -1))){
		return false;
	}
	return true;
}