function isEmail(str) {
  // are regular expressions supported?
  var supported = 0;
  if (window.RegExp) {
    var tempStr = "a";
    var tempReg = new RegExp(tempStr);
    if (tempReg.test(tempStr)) supported = 1;
  }
  if (!supported) 
    return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,3}|[0-9]{1,3})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}


function isvalidform(form) {
 	if (!form.recipient.value) {
		switch(form.i18n.value){
			case "en_US": 
				alert ("Please enter the first name of the person you are writing to");
				break;
			case "gm_GM": 
				alert ("Du hast vergessen den Namen des Empfängers anzugeben.");
				break;
		} 		
		form.recipient.focus();
		return false;
	} 
 	if (!isEmail(form.to.value)) {
		switch(form.i18n.value){
			case "en_US": 
				alert ("Please enter a valid recipient e-mail address");
				break;
			case "gm_GM": 
				alert ("Bitte trage eine gültige e-mail adresse für den Empfänger ein.");
				break;
		} 		
		form.to.focus();
		return false;
	} 
 	if (!form.comment.value) {
		switch(form.i18n.value){
			case "en_US": 
				alert ("Please enter your message");
				break;
			case "gm_GM": 
				alert ("Du hast noch keine Nachricht eingegeben.");
				break;
		} 		
		form.comment.focus();
		return false;
	} 	
 // if everything is ok proceed the form
 return true;
}