function isEmpty(strng) {
var error = "";
  if (strng.length == 0) {
	 error = "A mandatory field has not been filled in.\n"
  }
return error;	  
}

function checkEmail (strng) {
	var error="";
	if (strng == "") {
	   error = "You didn't enter an email address.\n";
	}

	var emailFilter=/^.+@.+\..{2,3}$/;
	
	if (!(emailFilter.test(strng))) { 
	   error = "Please enter a valid email address.\n";
	} else {
		//test email for illegal characters
		var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/
		if (strng.match(illegalChars)) {
			error = "The email address contains illegal characters.\n";
		}
	}
	return error;    
}

function checkForm(theForm) {
	var why = "";
	why += checkEmail(theForm.email.value);
	why += isEmpty(theForm.name.value);
	why += isEmpty(theForm.city.value);
	why += isEmpty(theForm.province.value);
	if (why != "") {
	   alert(why);
	   return false;
	}
return true;
}