// non-empty textbox
function isEmpty(strng, fname) {
	var error = "";
	  if (strng.length == 0) {
	     error = "The "+ fname +" 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;    
}